MUSEUM OF COMPARATIVE ZOOLOGY. 335 



Cionella Gloynei, Gibbons, n. sp. 



Under stones at CuraQao. Mr. J. S. Gibbons, (PI. I. Fig. H.) 

 Both jaw and lingual membrane are as usual in this genus and its allies. 

 (See Terr. Moll. U. S^ V.) The figure gives one central and its adjacent lat- 

 eral tooth. 



Pupa contracta, Sat. 



To the synonymy add Pupa Cincinnutiensis, Judge, Quarterly Journal of 

 Conchology, I. 343, fig., 1878. 



Hemitrochus Milleri, Pfr. 



Fortune Island, Bahamas. Dr. J. J. Brown to Mr. Bland. 



Jaw arched, high, ends blunt, scarcely acuminated : anterior surface Avith one 

 single rib-like prominence, extended into a decided median projection to the 

 cutting edge of the jaw. (PI. I. Fig. B.) 



Lingual membrane with about 33-1-33 teeth. PI. I. Fig. A shows the grad- 

 ual change from centrals to extreme marginals. The same type of teeth has 

 been noticed by me in varians, Troscheli, graminicola, and gallopavonis. These 

 species differ, however, from Milleri by having no rib-like prominence on the 

 anterior surface of their jaw, but a simple median projection to its cutting edge. 

 Like variation as to the presence or absence of ribs on the jaw has been no- 

 ticed by me in Dentellaria and other genera, a fact throwing doubt on the value 

 of the character of ribs on the jaw as of generic weight. 



Plagioptycha Duclosiana, Fi:B. 



Exuma, Bahamas. Dr. J. J. Brown to Mr. Bland. 

 Jaw as described under Hemitrochus Milleri. 



Lingual membrane with about 30-1-30 teeth. The changes from central to 

 marginal teeth are shown in PI. I. Fig. C. 



Mierophysa Stearnsi, Bl. 



Olympia, "Washington Territory. H. Hemphill. 



From an examination of the jaw and lingual dentition it appears that this 

 species is not a Zonites, as originally described, but rather a Mierophysa, like 

 M. Lansingi and M. Ingersolli With the former it shares the peculiarity of 

 having a ribbed jaw and aculeate marginal teeth to its lingual membrane, (See 

 Terr. Moll., V. 172, Fig. 21.) 



The jaw has over 19 ribs of the same type as those of M. Lansingi (1. c). 

 (See PI. L Fig. N.) A portion only of the jaw is figured. 



The lingual membrane (PI. I. Fig. M) has four laterals on each side of the 

 central tooth. 



Triodopsis vultuosa, Gould. 



Texas. Professor A. G. Wetherby. On PI. II. Fig. C, is given a figure of 

 the dentition of this species, which I have described on p. 313 of Terr. Moll. 

 U. S., Vol. V. 



