PLATE XXXVII. 
1. Pleurotoma Attenuata. (Slender Pleurotoma.) Fusiform; spire, with nine volutions, with well-marked suture; each with 
a series of blunted tubercles; body, with five or six longitudinal costa), crossed by many, undulous ribs, with man}’ fine strim; aper¬ 
ture elongated, narrow; diameter of shell one-fourth its length. 
2. P.Exorta. ( Risen Pleurotoma.) Elongated, turreted ; base conical; spire, with nine or ten inflated volutions; with twelve 
or fourteen, longitudinal cost® ; length of aperture and beak equal to two-fifths of length of shell ; canal short, slightly curved ; outer 
lip thin; inner lip reflected on columella. 
3,4. P. Brevlrostra. ( Short-beaked Pleurotoma.) Elongated, turreted ; body short; spire long, with ten or eleven volutions, 
separated by deep suture; with many, elevated, longitudinal ribs, crossed by many spiral stria} ; aperture obovate; canal narrow, 
curved; outer lip thin, inner lip smooth, reflected on columella. 
5. P. Semicolon. ( Semicolon-marked Pleurotoma.) Elongated, turreted; spire with four or five inflated volutions, with granu¬ 
lated margins; aperture ovate, one-third length of shell ; canal nearly straight ; outer lip thin on edge; pillar-lip smooth, reflected 
on columella. 
6. P. Acuminata. (Acuminated Pleurotoma.) Greatly elongated; body with nine or ten, inflated volutions, with fimbriated 
margin; apex acute; with many, longitudinal ribs, and many fine strias; aperture oblong-ovate; canal wide. 
7. P. Comma. ( Comma-marked Pleurotoma.) Elongated, turreted; spire, with five or six volutions; with many, longitudinal 
ribs, pointed like commas ; with a few, acute, spiral striae ; aperture oblong-ovate ; canal short, slightly curved. 
8,9. P. Lsevigata. (Smooth Pleurotoma.) Elongated, turreted, smooth; spire, with seven vcntricose volutions, with well- 
marked suture; with longitudinal rib 3 ; with a few, spiral stria); aperture oblong-ovate; canal, short, straight, narrow. 
10. P. Colon. (Colon-marked Pleurotoma.) Fusiform; with six or seven subturreted volutions; apex acute; suture deep ; with 
fine striae, crossed by longitudinal undulations ; base conical ; aperture oblong-ovate. 
11. P. Rostrata. (Beaked Pleurotoma.) Fusiform; spire, with eight or nine, convex volutions; with short, broad, longitudinal 
ribs; crossed by spiral ridges and narrow, undulating ribs; aperture ovate; canal long, narrow, straight. 
12. 13. P. Priscus. (Ancient Pleurotoma.) Fusiform, turreted, smooth; spire with eight convex volutions; apex sharp; outer 
lip wing-shaped; aperture elongated, oblique ; inner lip reflected on columella. 
14. P. Fusiformis. (Spindle-shaped Pleurotoma.) Elongated; fusiform; body long; spire short, with seven volutions, sub- 
carinated; lower portion of spire, with eight or nine, longitudinal ribs; the whole, with spiral stria); aperture oblong, lanceolate ; 
canal widish; outer lip rather thick; inner lip reflected on columella, transversely striated. 
15,16. Cerithium Funatum. (Corded Cerithium.) Conical, elongated; apex pointed; spire, with nine or ten volutions, each 
with two crenulated ridges ; aperture quadrangular; canal slightly twisted, short ; pillar-lip reflected on columella. 
17. C. Cornucopia. (Horn of Plenty Cerithium.) Subulate, turreted, punctuated; with about thirty volutions; tubercles on 
upper margin gradually increase; whole surface with minute punctures disposed in lines; aperture quadrate ; canal short, narrow, 
curved; its edge rising on plaited columella ; outer lip semicircular ; columella, with three, strong, oblique plaits. 
18. C. Giganteum. (Gigantic Cerithium.) Subulate; body short; spire very long, with many, punctured volutions; suture 
shallow, narrow ; with six or seven, transverse stria}; aperture ovate; columella, with four plaits. 
19. Potamis Duplex. (Doubled Potamis.) Subulate, conical; body short; spire, with eleven or twelve, flat, tapering volutions ; 
upper ones, with two spiral belts of tubercles, lower ones with three ; aperture small, roundish; canal, twisted, oblique, short; outer 
lip waved. 
20. P. Dubius. (Doubtful Potamis.) Subulate, turreted; spire, with ten volutions, with spiral carina of sharp, ovate tubercles 
near centre and two series of lesser tubercles below; aperture nearly circular; canal short, twisted. 
21. P. Politus. (Polished Potamis.) Subulate, smooth, shining, turreted, with longitudinal undulations; spire, with ten or eleven 
volutions ; suture distinct; carina spiral, with long, oblong tubercles ; aperture circular ; canal short, curved. 
22. 23. C. Gemminatum. ( Gemmed Cerithium.) Elongated, turreted, conical, smooth ; spire, with ten or eleven, turreted volu¬ 
tions ; apex acute; each volution, with seven or eight pairs of longitudinal volutions ; body, with two rows of minute tubercles; 
aperture orbicular; canal slightly recurved; outer lip even ; inner lip reflected on columella. 
24. P. Plicatus. (Wrinkled Potamis.) Subulate, conical; body large, ventricose ; spire, with ten or eleven volutions, with longi¬ 
tudinal plaits and three or four, spiral sulci; aperture subovate, oblique; canal wide, twisted; outer lip crenulated; pillar lip 
smooth, reflected on columella. 
25. P. VentPicosus. (Bellied Potamis.) Conical, turreted; spire, with nine or ten longitudinally ribbed and spirally striated 
volutions, each with two or three strife; base convex ; aperture orbicular; canal very short, slightly curved; outer lip but little 
twisted; inner lip reflected on columella. . - , . 
26. P. Cinctus. (Girdled Potamis.) Subulato-conical; body short, spire long, with ten or eleven, inflated volutions; apex 
obtuse; each volution with three belts of granules and two carina); aperture sub-rotund; canal longisli; columella, with single 
1 27. P. Acutus. (Acute Potamis.) Conical-turreted; spire, with seven or eight, bi-carinated volutions; apex acute; base convex, 
bi-striated; apertnre orbicular; canal short, narrow, curved; outer lip inflected. ; , 
28,29. C. Pyramidalis. (Pyramidal Cerithium .) Pyramidal, turreted; spire, with nine or ten volutions, with six, prominent, 
tuberculated ribs, with three, transverse, obtuse carina), each with three tuliercles ; body volution with six, compressed volutions, and 
seven or eight curium; whole surface, with minute, spiral strife; aperture orbicular, with short, twisted canal; outer lip expanded, 
undulous; pillar lip reflected on columella. . ._ . w _ . . 
30, 31. P. Rigidus. (Rigid Potamis.) Conical, smooth ; spire, with seven or eight volutions; suture shallow, narrow; whole 
surface with regular, curved grooves; aperture oval; canal, short, straight; outer lip expandet. . 
32. P- Intermedius. (Intermediate Potamis.) Pyramidal; with twelve or thirteen volutions ; w ith thick, crenulated carina and 
sharp strim; aperture sub-ovate; canal short and slightly bent. _, . .. _ 
:>3. P. Margaritaceus. (Pearly Potamis.) Conical, turreted; spire long, with ten or eleven, vcntricose volutions, each with five, 
spiral bands of bead-like tubercles; aperture sub-ovate, oblique; canal rounded, oblique ; outer lip expanded; inner lip smooth, 
V/concavus. (Concave Potamis.) Subulate, conical; with shallow, transverse striae; spire, with nine or ten volutions; 
with longitudinal, irregular costfe; aperture circular; canal short; outer lip enlarged; columella.smooth; base> convex. 
35. P. Funiculatus. ( Rope-like Potamis.) Pyramidal; spire, with ten or eleven volutions ; suture shallow . w itli four, crenulated, 
rope-like carina); aperture circular; canal short, twisted; margin of outer lip plain. 
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