470 Additional Remarks upon 



Art. IV. Additional Remarks upon the proposed Genus Cypr<B- 

 cdssis. By Samuel Stutchbury, Esq., A.L.S., Curator of the 

 Bristol Institution 



My attention having been called to some observations by 

 Mr. G. B. Sowerby, and another correspondent, upon my 

 proposed new genus Cypraecassis, described in the Fourth 

 Number of the New Series of your Journal, p. 214., I am 

 induced to offer a few additional remarks upon the subject, 

 especially as I have been so fortunate as to receive from Bar- 

 badoes, during the last week, two specimens of Cypraecassis 

 testiculus, with their animals. 



Animal unisexual. Head distinct, with two conical tentacula. 

 Mantle membranous, extending the whole length of the ventral 

 disk ; free upon the sides, but terminating in a fold, which lines 

 the recurved canal of the shell. 



Ventral disk, or foot, thick, fleshy, crenated upon the edges, 

 having a longitudinal sulcus, by which it is enabled to fold 

 itself, upon withdrawing into the shell. No trace of an oper- 

 culum. 



When separating Cypraecassis from Cassis, I did not wish 

 it to be understood that I considered the genus Cassis to be 

 then perfect, for I am inclined to think that farther division 

 might with great propriety be made, removing from it such 

 species as C. ringens and pomum ; also dividing those species 

 with the wide mouth, and having occasional varices at inde- 

 terminate distances, such as C. glauca, granulosa, vibex, &c, 

 and elevating them into genera or subgenera, for the sake of 

 convenience ; being satisfied that such subdivisions tend ma- 

 terially to assist the student in the more ready determination 

 of the subject under his investigation. 



Taking C. madagascariensis, tuberosa, cornuta, flammea, 

 &c, as typical of the genus Cassis, they may be distinguished 

 from all others by the following characters: — 



Shell triangular, completing the mouth, or basal face, at 

 every two thirds of a revolution of the whorl, each additional 

 portion being completed without absorption or removal of the 

 internal protruding parts, such as the toothed outer or colu- 

 mella lips ; having an epidermis and a horny operculum. 



The varices, which Mr. G. B. Sowerby mentions as oc- 

 curring in certain examples of C. testiculus which have come 

 under his observation, I have also been enabled to trace; and, 

 if we mean the same, they are evidently merely a thickening 

 of the edge, produced by a temporary cessation of the growth 

 of the shell, most probably occasioned by a change in the 

 condition of the animal, such as a deprivation of proper food, 



