[ 29 ] 
V. Observations on Naticina and Dentalium, two Genera of Molluscous Animals. 
By the late Rev. Lanspown Gutupine, B.A. F.L.S. 
Read June 21st, 1831. 
THE zoologists of the old school, regarding only the shells, have always 
considered the Natice as closely allied to the true Nerite of Linnzeus, and 
have obstinately retained them under the same generic title, rejecting all the 
subgenera so properly instituted by modern writers. A very slight acquaint- 
ance with the animals will convince us that the Naticide form a distinct 
family from the Neritide, the two groups differing in many most important 
characters. The former are apparently blind; the operculum has no appen- 
dages; their useless tentacula are weak and turned back on the shell, while 
in the act of creeping the head and its organs are perfectly veiled by a broad 
expanded hood (cucullus), the sensitive contractile apex of which serves to 
guide its motions. At first sight they rather resemble the Budlidw than the 
INeritide : for these have prominent eyes, an exposed head and long projecting 
sensitive tentacula, and the operculum has testaceous appendages for firmer 
insertion into the foot. I have transmitted a drawing and description of the 
typical species of Naticina to my friend Mr. Swainson, who has promised to 
insert many of my drawings of West Indian shells in his beautiful work, 
entitled ** Zoological Illustrations." 
MOLLUSCA. : 
Fam. Naticiom, Guild. Neritidæ, Gray. 
Genus 1. Natica, Guild. Natice pars, Sowerby. 
Character genericus. 
Testa subglobosa v. obovalis, rard depressiuscula. 
Spira brevis: apertura integra, semiorbicularis, latere columellari obliquo, 
edentulo, calloso. 
