C^CTJM. 329 



extremity fixed in the hollowed-out chamber of the terminal 

 process of the shell ; it then extends to the stomach, accom- 

 panied by the liver in alternate transverse portions; this 

 organ is a light greenish mass formed of larger granules than 

 the ovarium, and the contrast in colour of the two substances 

 caused them to be observed without difficulty. 



The neck admitted of a close examination, and did not 

 exhibit the slightest traces of external reproductive organs ; it 

 would therefore appear that the animal must depend on its 

 own influences; however, there are doubts; and from the 

 concordance of all its organs with a large class of the Pectini- 

 branchous Gasteropods, it may, like them, be unisexual, though 

 the organs have escaped detection. In all the specimens 

 examined the ovarium was present in the usual place, and in 

 no instance appeared to be replaced by the testicle ; but the 

 discriminations of such minute organs cannot be depended on. 



The foot is short, narrow, and truncate anteriorly when in 

 action, sloping posteally to an obtusely pointed or rather 

 rounded termination, on the upper part of which end is fixed 

 the strong, circular, corneous, black-brown operculum, smooth 

 and conical on the surface attached to the foot, concave with- 

 out, and from its centre seven or eight fine close-set spiral 

 lines, not concentrical, fill up the area. 



The animal is not at all shy ; it shows itself in all directions. 



The generic term Caecum appears to be somewhat objection- 

 able in point of significance. On the discovery of the animal 

 I proposed to my friend Dr. Goodall, the late Provost of Eton, 

 the generic appellation of Dentaliopsis ; but Dr. Fleming is in 

 possession of the field, and has the undoubted priority, and 

 I may say, owing to my own neglect, in not launching the 



genus : 



" Hos ego feci, tulit alter honores." 



C. GLABRUM, Montagu. 

 C. glabrum, Brit. Moll. iii. p. 181, pi. 69. f. 5. 

 After a research, in which I almost despaired of success, I 

 had the good fortune to meet with two living vivacious speci- 

 mens of this species in the coralline zones of the Devonshire 



