Class Gastropoda
 
   
                     
                                     
 
   

ORDER ARCHAEOGASTROPODA

SUBORDER BELLEROPHONTINA

SUBORDER MACLURITINA

SUBORDER PLEUROTOMARIINA

SUBORDER TROCHINA

SUBORDER NERITOPSINA

 
   
-Species Descriptions-
 
   
SUBORDER BELLEROPHONTINA
 

   

Bucania sp. Hall, 1847 - Description from Wahlman, 1992

Description: Shell size small to large. Whorls are rounded or depressed and gradually expanding. The umbilicus is medium to large. Outer lip of aperture is thin, with broad, V-shaped sinus and central slit. Slit is shallow to quite deep. Selenizone is generally narrow, being slightly elevated, flat, or channellike. The inner lip of aperture is thickened in many cases. Shell surface is marked by transverse growth lines or lamellae and revolving threads. The revolving threads run normal to, and are generally interrupted by, growth lines. The growth lines in many specimens become lamellose in maturity, accompanied by a general thickening of the whorl laterally and posterolaterally.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 
          Bucania sp., MCZ 145368              
         
MCZ 145368: 14.5mm wide
             

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Loxobucania? aff. frankfortensis (Ulrich in Scofield, 1897) - Description from Ulrich and Scofield, 1897

Bucania frankfortensis Ulrich in Scofield, 1897, p. 891, pl. 16, fig. 30-33.
Loxobucania? aff. frankfortensis
(Ulrich in Scofield, 1897)

Description: Has subangular aperture, a thick inner lip, and coarse surface sculpture. Volutions are narrow and the height of the shell is greater than the width.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 
          Loxobucania? aff. frankfortensis, MCZ 145404              
         
MCZ 145404: 1mm wide
             

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Phragmolites compressus aff. Conrad, 1838 - Description from Wahlman, 1992

Phragmolites compressus Conrad, 1838, p. 119; Weller, 1903, p. 178, pl. 12, fig. 16-17; Knight, 1941, p. 242, pl. 9, fig. 2; Shimer and Shrock, 1944, p. 443, pl. 178, fig. 5; Wilson, 1951, p. 29, pl. 2, fig. 17-18.
Crytolites compressus
(Conrad). Hall, 1847, p. 188,p. 40A, fig. 2a-f; Hall, 1862, p. 40, fig.4; Chamberlin, 1883,p. 158, fig.; Lesley, 1889, p. 182, fig; Wahlman, 1992, p. 120, pl. 42, fig. 14, pl. 44, fig. 1-4.
Conradella compressa
(Conrad). Ulrich and Scofield, 1897, p. 906, not figured.
Conradella similis
Ulrich in Ulrich and Scofield, 1897, p. 906, not figured.

Description: Shell is small, narrow, and very gradually expanding. The whorls barely contiguous, embracing only the dorsal carina of the preceding whorl. Dorsal carina is prominent, slightly rounded, with faint lunulae. The dorsal slopes briefly concave near carina, then become evenly convex. Umbilical shoulders are sharply rounded and ventral slopes are slightly convex to nearly flat. The apertual outline is lanceolate, higher than wide. Umbilici are wide with a deep slit, apparently about on-half a volution. Growth lines are fine, closely spaced with very fine revolving lines visible in some specimens. Periodic corrugated growth lamellae are rather widely spaced, with five or six square re-entrants from shoulder to carina.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Phragmolites compressus aff., MCZ 145406              
         
MCZ 145406: 4.5mm wide
             

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Pterotheca undulata Hall, 1861 - Description from Wahlman, 1992

Description: Shell is large, broadly expanded, and generally wider than long with a subquadrangular outline. Coil is absent, the apex marginal, incurved to varying degrees, in many cases hooklike. The slit is more or less vertical to apertural plane, generating a prominent elevated dorsomedian keel from apex to anteromedian apertural margin, which is generally sinuate. The lateral shell surfaces convex, with comarginal growth lines, lamellae, or undulations, and in some cases with radial markings on either side diverging from apex along lines of attachment between ventral septum and ventral shell surface, thus defining a slightly elevated triangular are of dorsal shell overlying septum. Radial threads or cords are unknown. The septum is triangular, proportionate size and angles are variable, flat to convex-upward, with two short, diverging prongs at apical end in narrow space between septum and shell surface. The space between shell dorsum and septum is very narrow.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Pterotheca undulata, MCZ 145408              
         
MCZ 145408: 59mm wide
             

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    Sinuites cancellatus Hall, 1847 - Description from Wahlman, 1992

Bellerophon bilobatus Emmons (not Sowerby), 1842, p. 392, fig. 6; Hall, 1847, p. 184, pl. 40, fig. 3a-d; Miller, 1874, p. 306; Lesley, 1889, p. 81, fig.; Miller, 1889, p. 396, fig. 652.
Cyrtolites bilobatus
Emmons, 1855, p. 166, fig. 2, 3, 22, 24; pl. 17, fig. 10c.
Bellerophon cancellatus
Hall, 1847, p. 307, pl. 83, fig. 10a-c.
Protowarthia cancellata
(Hall). Ulrich and Scofield, 1897, p. 872, pl. 63, fig. 1-14; Weller, 1903, p. 175, pl. 12, fig. 3-5; Cummings, 1908, p. 971, pl. 39, fig. 6a-b; Grabau and Shimer, 1909, p. 611, fig. 817g-I; Knight, 1941, p. 279, pl. 6, fig. 3a-b.
Sinuites cancellatus
(Hall). Bassler, 1915, p. 1159; 1919, p. 313, pl. 50, fig. 37-39; pl. 55, fig. 12-21; Foerste, 1924, p. 205, pl. 34, fig. 6; Ruedemann, 1926, p. 62, pl. 8, fig. 6; Bassler, 1932, pl. 21, fig. 16-18; Shimer and Shrock, 1944, p. 441, pl. 176, fig. 24-25; Wilson, 1951, p. 25, pl. 2, fig. 11-12; Caster et al., 1955, pl. 1, fig. 16-17; Pope and Martin, 1977, pl. 1, fig. 16-17; Wahlman, 1992, p. 111, pl. 11, fig. 6-12.

Description: Shell is medium in size, involute, with closed umbilicus. It is generally subglobose, smoothly rounded dorsally and laterally, and the degree of convexity is variable. Sinus is moderately shallow and V-shaped, having well-rounded apex. The lateral apertural margins merge into well-rounded lobes and the aperture is distinctly wider than long. Parietal inductura are thin, folding over venter of coil onto umbilical region,and are marked by fine, wavy revolving lines. The shell ornament consists of fine, closely spaced growth lines crossed by even finer revolving lines, giving a faint cancellate appearance.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
      Sinuites cancellatus, MCZ 145427 Sinuites cancellatus, MCZ 145409      
     
MCZ 145427: 6mm wide
MCZ 145409: 27mm wide
     

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Sinuites globularis aff. (Miller and Faber), 1894 - Description from Wahlman, 1992

Bellerophon globularis Miller and Faber, 1894, p. 28, pl. 1, fig. 21-22.
Sinuites globularis
(Miller and Faber). Bassler, 1915, p. 1160; Wahlman, 1992, p. 114, pl. 10, fig. 1-13.

Description: Shell is moderately small and tightly coiled. The umbilicus is closed. Whorls are broad and inflated. Has dorsum with distinct, round dorsomedian ridge, bounded by shallow widening furrows, which in turn are bordered by low, rounded, diverging ridges. The aperture is broad and semicircular in general outline. Parietal deposits (calcareous deposits secreted onto walls of shell) are unknown, the sinus is deep, and lateral aperture lobes are well rounded. Growth lines are fine, closely spaced, and revolving lines are not known.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Sinuites globularis aff., MCZ 145461              
         
MCZ 145461: 23mm wide
             

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    Undulabucania punctifrons aff. (Emmons, 1842) - Description from Wahlman, 1992

Bellerophon punctifrons Emmons, 1842, p. 392, fig. 5; Lesley, 1889, p. 87, figs.
Bucania punctifrons (Emmons) Hall, 1847, p. 187, pl. 40A, fig. 1a-e; Ulrich and Scofield, 1897, p. 894, pl. 67, fig. 41-44; Raymond, 1902, p. 19, fig. 9-10; Weller, 1903, p. 177, pl. 12, fig. 10-12; Grabau and Shimer, 1909, p. 614; Bassler, 1932, pl. 13, fig. 16-17; Wilson, 1951, p. 27, pl. 2, fig. 21-23.
Undulabucania punctifrons (Emmons). Wahlman, 1992, p. 142, pl. 23, fig. 1-9.

Description: Shell is small to moderate in size, consisting of about three volutions and is gradually and evenly expanding throughout growth. Umbilici are relatively wide for genus. The whorls are rounded and subtrapezoidal in outline, with evenly and rather deeply convex dorsum, sharply rounded umbilical shoulders, flat and broad umbilical slopes that angle gently inward to shoulder of previous whorl, and concave ventrum covering surface of previous whorl. The aperture shows only very slight flaring as an adult, and has wide, fairly deep anterior sinus. The slit is quite deep, generating channellike selenizone bordered by thin, sharp ridge on either side. Shell surface is covered by evenly undulating, wavy growth lines which intersect to form fine, slightly raised, netlike meshwork. This sculpturing is present on juvenile whorls visible in umbilicus. Growth becomes coarsely lamellose in later growth.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
      Undulabucania punctifrons aff., MCZ 145469 Undulabucania punctifrons aff., MCZ 145466      
     
MCZ 145469: 9.5mm wide

MCZ 145466: 14mm wide

     

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SUBORDER MACLURITINA
 

    Lytospira sp. Koken, 1896 - Description from Knight et al., 1960

Description: Shell is openly coiled, some species hyperstrophic. Has broadly angular sinus in outer lip culminating at low bluntly angular spiral ridge near mid-line of upper surface. Some species cement shells or other foreign substances to outer surface.

Ecology: Most species are sedentary and lie flat on the seafloor living by ciliary suspension feeding.

 

 
          Lytospira sp., MCZ 145405              
         

MCZ 145405: 15.5mm wide

             

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SUBORDER PLEUROTOMARIINA
 

    Eotomarid sp. indet. - Description from Knight et al., 1960

Description: Shell turbiniform to trochiform. The outer lip slit is invariably present, generating a concave selenizone bordered by threads at approximately mid-height of whorl.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Eotomarid sp.indet., MCZ 145378              
         
MCZ 145378: 9mm wide
             

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    Lophospira milleri (Hall in Miller, 1877) - Description from Tofel and Bretsky, 1987

Murchisonia bicincta Hall, 1847, p. 177, pl. 38, fig. 5a-h; ?Meek and Worthen, 1868, p. 317, pl. 3, fig. 4; ?Miller, 1874, p. 315; not Rogers, 1858, p. 817, fig. 593; not Salter, 1859, pl. 4, fig. 5-7; not Whitfield, 1886, p. 311.
not Murchisonia bicincta M’Coy, 1846, p. 16; M’Coy, 1862, pl. 1, fig. 17.
not Pleurotomaria bicincta (Hall). Lindström, 1884, p. 106, pl. 8, fig. 15-25; ?Whiteaves, 1895, p. 122-123.
Lophospira bicincta (Hall). (part) Bassler, 1919, p. 294, pl. 39, fig. 1-5; not Ulrich and Scofield, 1897, p. 964, pl. 72, fig. 1-5; not Cummings, 1908, p. 967, pl. 40, fig. 16, 16a, 16b; not Grabau and Shimer, 1909, p. 632, fig. 856a-d; ?Ruedemann, 1901, p. 30.
?Lophospira pulchella Ulrich and Scofield, 1897, p. 982, pl. 73, fig. 46-48; Grabau and Shimer, 1909, p. 634, fig. 859i-k.
Murchisonia milleri (Hall). Miller, 1877, p. 244; ?Walcott, 1888, p. 237, fig. 3-4; ?Lesley, 1889, p. 430; ?Whiteaves, 1893, p. 320.
Lophospira milleri (Hall). Knight, 1941, p. 179, pl. 39, fig. 4a-b; not Wilson, 1951, p. 36, pl. 5, fig. 4. Tofel and Bretsky, 1987, p. 715, fig. 5.4, 5.5.
Loxoplocus(Lophospira) milleri (Hall). Knight et al., 1944, p. 449, pl. 2, fig. 1-2.

Description: Spires moderately high; coiling dextral, orthostrophic. The sutural indentation progressively deepens on abapical whorls; disjuncture absent. Umbilicus is sphaneromphalous and has outer lip with sinus. The peristome is usually broken and has an angular profile. Sutural shelf is narrow, concave, and nearly horizontal. The shoulder carina are sharp, keel-like and the upper ramp is wide and progressively more concave in abapical direction. Selenizoneis trilineate and the middle thread is sometimes closer to lower than upper thread. Lower ramp is slightly concave and the lower shoulder carina on underside of separated and final whorls. The base is ventricose to umbilicus. Growth lines are fine, evenly spaced, straight on sutural shelf, abaperturally swept on upper ramp, and turn sharply at selenizone producing chevron-like lunulae. They areabaperturally swept on lower ramp and straighten below lower shoulder carina toward the umbilicus. Internal morphology and shell mineralogy are unknown.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Lophospira milleri, MCZ 145400              
         
MCZ 145400: 10.5mm wide
             

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Trochonema umbilicata Hall, 1847 - Description from Ulrich and Scofield, 1897

Pleurotomaria umbilicata Hall, 1847, p. 43, 175.

Trochonema umbilicata Salter, 1859, p. 27, pl. 6, fig. 3.

Trochonema umbilicatum Hall, 1847. Ulrich and Scofield, 1897, p. 1047, pl. 27, fig. 1-8.

Description: Shell has rather low volutions, with a shoulder-like flat space bordering the suture and taking up about one-third of the width of the upper side, with the remaining two-thirds being a concave slope to the peripheral band. This is almost exactly vertical to barely concave. The under surface from the lower peripheral angle to the subcentral ridge enclosing the umbilicus is a nearly flat slope. The shell is rather thin and the apertural margin is much less expanded. Aperture is very oblique. The surface markings are obscure on all but the last whorl. They are not coarse and often somewhat irregular. 

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Trochonema umbilicata, MCZ 145464              
         

MCZ 145464: 12mm wide

             

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SUBORDER TROCHINA
 

    Cyclonema bilix aff. (Conrad, 1842)  
      Cyclonema bilix aff., MCZ 145375 Cyclonema bilix aff., MCZ 145376      
     
MCZ 145375: 10mm wide
MCZ 145376: 17.5mm wide
     

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Globonema salteri cf. (Ulrich+Scofield, 1897)

Globonema salteri cf. (Ulrich and Scofield, 1897)

Description:

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Globonema salteri cf., MCZ 145379              
         
MCZ 145379: 7mm wide
             

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    Holopea symmetrica Hall, 1842 - Description from Knight, 1932

Holopea symmetrica Hall, 1847, p. 170, pl. 37, fig. 1; White, 1895, p. 85; Weller, 1903, p. 186, pl. 12, fig. 26-27; Knight, 1932, p. 475, fig. 1a-f, 2a-b.

Description: Shell is moderately small with straight sides, evenly and roundly convex whorl profile, and deep sutures. The roundness of the whorl profile continues uninterruptedly across the base and into the umbilicus. The aperture is sub-circular with the apertural margin only in contact with the previous whorl for a short distance. Ends of the free margins are connected by a thin, parietal inductura. The outer lip is oblique in side view and only very slightly sinuous. The inner lip is thin, nearly vertical, and slightly reflexed. Columella is narrowly phaneromphalous. Shell ornamentation of very fine growth lines superimposed on irregular and indistinct transverse undulations. The nucleus has not been observed.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
      Holopea symmetrica, MCZ 145381 Holopea symmetrica, MCZ 145396      
     
MCZ 145381: 14mm wide

MCZ 145396: 11.5mm wide

 

     

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SUBORDER NERITOPSINA
 

    Hormotoma gracilis Hall, 1847 - Description from Ulrich and Scofield, 1879

Murchisonia gracilis Hall, 1847, p. 22.
Muchisonia gracilens Whitfield, 1889, p. 53, pl. 8, fig. 14.
Hormotoma gracilis Hall. Ulrich and Scofield, 1897, p. 1014, pl. 20, fig. 18-36, 42-43.

Description: Shell is small, slender and rounded, generally with a slight angulation, on which lies the slit band (the trace of the slit around whorls). Sutures are simple and deep. Growth lines are fine, bending strongly backward from the suture to the slit band, and beneath this curving very strongly forward. The aperture is a little higher than wide, and rounded. Inner lip is reflected, forming a slightly twisted and thickened columella.

Ecology: Algal grazers, rasp algae from hard surfaces or feed on erect green algae.

 

 
          Hormotoma gracilis, MCZ 145398              
         
MCZ 145398: 12mm long
             

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