Genus Cypma. 233 



(c) seniiplota (Mighels), 1848. fiinbriatu la (Sowh.), 1870. 

 Undoubtedly synonyms. I have two specimens labelled by 

 the latter name, in no way excepting in small size (-4 inch) 

 differing from the smooth white spotted liviacina (Lamk.). 

 As Mr. Roberts suggests (Man. Conch. Cyp., p. 194) C. spadix 

 (Mighels) is the immature state of this variety. 



The smaller Trivice have been so satisfactorily worked 

 out by various eminent Conchologists, especially Gray 

 and Gaskoin, as to be now almost perfectly systema- 

 tized. As a rule they are fairly constant ; and their 

 differentiation is not a matter of undue difficulty, if the 

 presence or absence of the dorsal impression or sinus, and 

 the colour, quality and quantity of ribs, and disposition of 

 marking be regarded. 



***** 



Lastly, with respect to the other species and varieties of 

 Cyprcea proper, e.g. the cerviis and hiriindo sections, xantJio- 

 don^picta and allies, and others, complete acquiescence in, 

 and acceptance of the diagnoses in Sowerby's " Thesaurus 

 Conchyliorum " must be taken as valid reasons against the 

 necessity of further alluding to them in this paper. 



(XIV.) Doubtful species. 



C. cxiiiiia (Gray), Proc. Zool. Soc., 1849, is a fossil from 

 Tasmania, very near C. ttmbilicata (Sowb.) It was supposed 

 by Dr. J. E. Gray, the describer, to have become only 

 recently extinct, after the fashion of Btdhmis aiiris-vidpiiia 

 (Chemnitz) from S. Helena,* which, if one can compare the 

 causes which lead to the annihilation of a marine form 

 with those affecting a terrestrial species, seems to have been 

 of equally restricted range, and to have eventually died a 

 natural death. 



a Cf. Wollaston, Testacea Atlantica, p. 547. INIelliss. S. Helena, p. 121. 

 pi. xxii., f. 2, 2^. 



