REPORT ON THE MOLLUSCA. 23 



Cuspidaria ( = Ncwra). 



The structure of the genus Cuspidaria was till recently unkno\\ii. In 188G, in a 

 query to Nature,^ Mr. Wm. H. Dall, conchologist to the Washington National Museum, 

 asked that facts which he had observed in the structure of this genus should be tested 

 on European specimens. He thought it had neither gills nor labial palps. The reser- 

 vations with which he stated these facts arose from his not having made his observations 

 on specimens in a perfect state of preservation. 



The query remained unanswered until I took up the question.^ 



Meanwhile, Dall had republished his statement in greater detail, but still with 

 the same reservations : " If the writer has not been misled by contraction of the parts 

 under the action of alcohol •,"^ " if confirmed by the study of fresh specimens." * 



It would, however, be interesting to test the facts mentioned by Dall in his paper, 

 especially as Gwyn Jeffreys ^ attributes to Cusp>idaria (Nesera) " pink gills." It was 

 therefore with great satisfaction that I found three specimens, each representing a dif- 

 ferent species of the genus Cuspidaria, in the Challenger collection entrusted to me. 



22. Cuspidaria curta, Jeffreys. Station 75 ; 450 fathoms. 



23. Cuspidaria fvagilissima, Smith. Station 145 ; 300 fathoms. 



24. Cusp)idaria platensis, Smith. Station 320 ; 600 fathoms. 



The structures which I shall describe and figure are based on the studv of the 

 three specimens already mentioned, and of specimens of Crispidaria rostrata, Spengier, 

 obtained from the Zoological Station at Naples,* that is to say, the best prepared 

 specimens which can be found. Indeed, so well are they preserved by the clever con- 

 servator Salvator Lo Bianco, that one can cut sections and work with them as with 

 fresh specimens. 



It follows, therefore, that my examination has included a certain number of species, 

 and several specimens of one of these species. What I have observed, then, does not 

 constitute an individual variation or a monstrosity, but a normal, invariable disposition 

 which is not peculiar to certain forms, but common to the entire genus. The different 

 species resemble each other closely, and I shall not describe them separately. 



The mantle is closed ventrally, in the posterior half of its length at least, and even 

 a little more in certain species, as in Cuspidaria curta ; the pedal aperture is therefore 

 normal enough. The two pallial lobes are excessively delicate and transparent, as was 

 already known. 



1 Vol. xxxiv. p. 122. 



^ Sur des Pelecypodes sans branchics. Complex retahis, t. cvi. p. 1029. 



" Report on tlie Mollusca, Ivc. cit., p. 293. * lint/., p. 302. 



' British Conchology, vol. iii. p. 49. 



'• I have to thank I'rofestor AlIou Dohrn, who kindly sent me these Bpecimens. 



