2U 



ON THE TOrOGEArilY AND GI^OLOGY 



or only of specific value, can only be determined on studying other species, should 

 they be found. . _ - - • 



E. trim cat a. Gabb, n. s. 



Shell acuminately oblong, spire liigli, whorls nine or ten at least ; apex always truncated, so that usually not 

 more than two whorls are preserved ; surface of whorls broadly rounded, slightly concave near the suture which is 

 linear and distinct. No ornaments except some obscure revolving lines, not always present. Aperture acute behind, 

 inner lip sinuous, encrusted, simple; outer lip simple straight, produced in advance ; anterior sinus broad, shallow 

 and oblique. Length of body whorl of an average sijecimen 1.15 inch ; width .8 inch. 



The truncation of the apex is not an accidental character, but one of at least 

 specific value. Very young shells, only one-fourth of an inch long show it in the 

 same manner as the adults which, with the spire, would have a length of two inches. 



CYCLOPS. Montf. . " ' 



C. angulatus, Gabb, n. s. 



Shell minute, translucent, discoidal, whorls rounded above and below and having an angle or carina in the mid- 

 dle, which becomes obsolete in the adult shell on approaching the aperture. Body whorl enveloping the others above, 

 the suture being carried to the apex, but leaving it in the mature shell, so that the top of the shell shows the suture 

 as a straight line bent at a right angle in the middle, and running from the apex across the body whorl to the margin. 

 Aperture laterally expanded ; umbilical callus small and slightly concave. Surface minutely striate by tine revolv- 

 ing lines. 



A peculiar shell recognizable by its covered top and carinate body whorl. 



C. depressus. Gabb, n. s. ■' 



Shell very small, discoidal, spire flat, whorls rounded, increasing rapidly in size ; body whorl enveloping the 

 others, the suture running in a straight line from the apex. Aperture large, callus small ; surface polished. 



It difliers from the preceding in the whorls being regularly rounded, instead of 

 carinated, and in their increasing more rapidly in size. The top of the shell also is 

 flatter. ' ■ S 



CUMA. Humplu ' ' , ( ' 



C. tectum. Kiener, sp. 



Pyrula tectum. Kiener. ' • ^ 



Bmcimom tectum, Gray. Woods. Ind. Test., Supp. ' ' . 



TvrbineUa, tectum, Rve. Icon. Conch. Turbinella, sp. 40. 



This well known Panama shell is very common in the Dominican beds, and goes 

 through an astonishing series of variations. I have it with a rounded body, without 

 a tubercle, and varying from that to a broadly angulated and umbilicated form, with 

 six immense tubei'cles on the angle. Between these, and other extremes, 1 fortunatel}'^ 

 possess complete series connecting them without question. 



• HARP A. Lam. '' 



H. rosea. Lam. ' •■ ' . . - 



A single nearly fuU-groAvn specimen of this African species, has all of the charac- 

 ters possessed by recent shells of corresponding size in the Academy's collection. 



