233 



NOTES ON THE CAPUT-SERPENTIS GROUP OF THE 

 GENUS CYPR^EA. 



By J. COSMO MELVILL, M.A., F.L.S., and ROBERT STANDEN. 



(Read before the Conchological Society, December 14th, 1898.) 



Eleven years ago, in the " Survey of the Genus Cyproea," 1 the 

 sequence of the group of certain of the section Aricia, was thus given : 



C. moneta L. 



C. obvallata Lam. 



C. annulus L. 



C. caput-anguis Phil. 



C. caput-serpentis L. 

 C. caput-draconis Melv. 

 C. mauritiana L. 

 C. arabica L. 



Of these C. caput-anguis was a doubtful species, and should, we think, 

 have been classed as a variety of the common C. caput-serpentis ; 

 except for this little change, the order need be in no way altered. A 

 pure white variety of C.-serpentis, recently acquired by one of us, 

 serves as a fresh and closer connection with C. annulus and C. moneta, 

 whilst the Australian variety of the same species, with more or less 

 straight sides and dorsal convexity, links the type superficially with 

 the distinct C. caput-draconis, this again being basally, except in size, 

 an almost complete replica of the larger C. mauritiana L. 



C. caput-anguis Phil. 2 was unfortunately not figured, nor do we know 

 where the type is located. Accordingly, it must be to some extent un- 

 certain whether a specimen relegated to this obscure " species " is 

 rightly named. 



In a most instructive paper 3 Mrs. Agnes F. Kenyon maintains that 

 two small specimens in her possession are the true C. caput-anguis 

 Phil. She figures them, both dorsally, laterally, and basally, and com- 

 pares them with the larger Cowry, from the Sandwich Isles and 

 Australia, which has been at various times regarded as C. caput-anguis. 

 They agree with the dimensions and coloration given by Dr. Philippi, 

 and we consider it very possible she has lighted on his species, but, 

 even if so, we are by no means sure of its real distinctness from 

 C. caput-serpentis. We are sorry Mrs. Kenyon's examples are no longer 

 in this country, and that we had not an opportunity of comparing 

 them minutely with others. We cannot, however, see (from the figures 4 ) 

 that the shell is " more oblong and pyriform in shape " than the 

 variety of C. caput-serpentis, also figured. 5 The dorsal surface appears 

 similar in. both forms ; the base, however, being more convex in 



1 Manchester Memoirs, ser. 4, vol. 1, p. 184-252, 1888. 



2 Zeitschr.f. Malakozool., Jahrg. 6, p. 24, 1849. 



3 Proc. Mai. Soc, vol. 3, p. 77, 78, 1898. 



4 OJ>. cit., p. 78, fig. 1. 



5 Op. cit., p. 78, fig. 2. 



