CHASTER : BRITISH MARINE MOLLUSCA. 59 



an assertion that this species has not been found in British 

 waters since its discovery by Jeffreys. I have myself met with it 

 in Guernsey dredgings. Still more unfortunate, however, was 

 Jeffreys' statement in his " British Conchology " that it is the 

 fry of C. rhombea, Berk. As the Annals and Magazine of 

 Natural History for 1839 may not be readily accessible to many 

 conchologists I have given below a figure of this species and an 

 outline of the true fry of C. rJiombca for comparison. 



FIGURE 4, 



CrcncUa pcUcidii, Jeff, x 30. Crenclla rhombea, Berk, x 30. 



Cerithiopsis clarkii, Forbes and Hanley. 



1848-53, C. chu'kii. F. & H., Brit. Moll.; vol. iii., p. 368, pi. ciii., fig. 6. 



As a representative of this form I have but a dead specimen 

 not in very good condition from Guernsey dredgings sent by Mr. 



E. R. Sykes. 



Jeffreys in his " British Conchology " dismisses it Avith a 

 scanty description as a monstrosity of C. tuhercularis, Montg., 

 obtained by Mr. Clark, at Exmouth, and by himself at Guernsey. 

 In his "Lighting" and "Porcupine" papers he similarly 

 disposes of it and gives as synomyms C. hilineata and C coppolae. 

 The Rev. R. Boog Watson, in his excellent " Cerithiopsides from 

 the eastern side of the North Atlantic," '•' also confounds it with 

 the Mediterranean shell. Now C. coppolaz, Ava.d. { = biliiieata, Brus., 

 non Homes) is certainly quite distinct from C. tuhercularis, its 

 apex as well as its sculpture and shape, being very different. 

 My Guernsey shell Monterosato designates " le vrai C. Clarkii, 



F. & H.," and declares to be distinct from C. coppola, an opinion 

 with which I entirely agree. The figure in " British Mollusca " 

 well represents it. I am anxious to learn whether others who 

 have specially studied the moUuscan fauna of the Channel 

 Islands can give further information regarding this interesting 

 species and whether or not it is to be considered extinct. 



N.B. — In figure la the whorls are insufficiently flattened and sloping, and 

 in figure 4 the shell is too equilateral and the umbo too acute. 



* JiDurn. Lin. Soc, 1885, Zoiilogy, vol. xix., p. 92. 



