CERIT H lUM 



Plate XVIII. 



Species 133. (Mus. Cuming.) 



Ceritiiiim gibberulum. Cerith. testa minutd, ovali, 

 gibbosd, fused, lev'der lonij'i tiulinaliler plicatd, lineis 

 elevatis fusco-tiigreseentibus crenulatis einetd ; an- 

 fractibus novem, subventricosis ; aperlurd ovatd, colii- 

 melld brevi, canali brnissimo, labro iitcrassato, rotimdo, 

 intus crenulato. 



The little-gibbous Cebithium. Shell minute, oval, 

 gibbous, brown, lightly longitudinally plaited, girt 

 with elevated, blackish-browu, creuulated lines ; 

 whorls nine, rather ventricose ; aperture ovate, colu- 

 mella short, canal very short, outer lip thickened, 

 round, crenulated within. 



C. B. Adams. 



Hab. North America. 



A very smaU shell, with thickened outer lip and varices. 



Species 124. (Mus. Cuming.) 



Ceritiiitjm iota. Cerith. testd minutissimd, conicd, 

 nigrescente, infra siibcomplanatd ; anfractibus panels, 

 spiraliter triseriatim tuberculatis, lungitudinaliter le- 

 viter pUcatis ; aperturd subtrigond, columelld brevi, 

 canali aperto, brevissimo, labro vix incrassato. 



The dot Cekithium. Shell very minute, conical, blackish, 

 rather flat beneatii ; whorls few, tuberculated in three 

 spiral rows, slightly plaited lengthwise ; aperture 

 rather trigonal, columella short, caual open, very 

 short, outer lip very slightly thickened. 



C. B. Adams. 



Hub. Jamaica. 



Species 125. (Mus. Cuming.) 



Cerithium parcum. Cerith. testd pared, albd, pgrami- 

 datd, longitudinaliter plicatd, plicis rotimdis, spiraliter 

 costatd, costis ad plicas tubercuUferis ; anfractibus 

 panels, leviter ventrlcosls, ultimo subfuslformi ; aper- 

 turd ovatd, columelld rectiusculd, elongatd. 



The moderate Cerithium. Shell small, white, tapering, 

 longitudinally plaited, plaits round, spirally ribbed, 

 ribs tuberculated on the plaits ; whorls few, slightly 



ventricose, the last rather fusiform, aperture oval, 



columella rather straight, elongated. 

 Gould. 

 Hab. Mazatlan. 



Species 126. (Mus. Cuming.) 



Cerithium altum. Cerith. testd elongatd, angustd, 

 pallide fulvd, spiraliter castaneo fasclatd, minuiisslme 

 decMssatd, varicibus albis ; anfractibus rectiuscuUs, 

 ultimo subrotundato ; aperturd ovatd, columelld rectd, 

 labro sublncrassato. 



The tall Cerithium. SheO long, narrow, pale-fawn, 

 spirally banded with chestnut, minutely decussated, 

 varices white, whorls rather straight, the last slightly 

 rounded ; aperture ovate, columella straight, outer 

 lip thick. 



Sowerby. 



Hab. ? 



Differing from C. lacertinum, C.elongatmn, etc., in fine- 

 ness of sculpture. It is delicately banded with light-chest- 

 nut. 



Species 127. (Mus. Cuming.) 



v^erithium tricarinatum. Cerith. testd elevatd, an- 

 gustd, fulvd; anfractibus turrltls, rotundls, spiraliter 

 vallde trlcarlnatis, longitudinaliter pllcatls, suturd ex- 

 cavatd ; aperturd subquadratd, columelld subtortuosd, 

 canali brevissimo. 



The three-keeled Cerithium. Shell elevated, nar- 

 row, light-brown; whorls turreted, rounded, with 

 three strong spiral keels, longitudinally plaited, suture 

 hollow ; aperture rather square, columella rather tor- 

 tnous, canal very short. 



Pease. 



Hab. Sandwich Islands. 



The keels in each whorl of this shell are strong and 

 prominent, and are crossed at regular intervals by longi- 

 tudinal plaits, the interstices forming rather square hol- 

 lows. 



December, 1865. 



