136 BULLETIN 111, UNITED STATES NATIONAL MUSEUM. 



This is the slenderest species of the group. It is also characterized 

 by its exceedingly small size, feeble swelling, and its very regular 

 curvature. 



CADULUS (GADILA) VERRILLI. new species. 



Plate 19, fig. 13. 



1880. Cadulus propinquus, Verrill, Proc. U. S. Nat. Mus., vol. 3, p. 395 (not of 



Sars, 1878). 

 1880. Cadulus propinquus, Verrill, Amer. Journ. Sci., vol. 20, p. 392. 

 1880. Cadulus Jeffrey sii, Verrill, Amer. Journ. Sci., vol. 20, p. 392 (not of Mon- 



terosato, 1875). 

 1880. Cadulus jeffreysii, Verrill, Proc. U. S. Nat. Mus., vol. 3, p. 395 (not of 



Monterosato, 1875). 

 1882. Cadulus propinquus, Verrill, Trans. Conn. Acad. Arts and Sci., vol. 5, 



p. 568, pi. 58, figs. 31, 32 (not of Sars, 1878). 

 1882. Cadulus jeffreysii, Verrill, Trans. Conn. Acad. Arts and Sci., vol. 5, pt. 2, p. 



559 (not of Monterosato, 1875). 

 1885. Cadulus subfusiformis, Verrill, in Rept. of Com. of Fish and Fisheries for 



1883, p. 573 (not of Sars, 1865). 

 1885. Cadulus propinquus, Bush, in Rept. of Com. of Fish and Fisheries for 1883, 



p. 717 (not of Sars, 1878). 

 1885. Cadulus jeffreysii, Bush, in Rept. of Com. of Fish and Fisheries for 1883, p. 



717 (not of Monterosato, 1875). 

 1889. Cadulus jeffreysii, Dall, Bull. Mus. Comp. Zool., vol. 17, p. 430 (not of 



Monterosato, 1875). 

 1898. Cadulus (Gadila) jeffreysi, Pilsbry and Sharp, Tryon's Man. Conch., vol. 



16, p. 164, pi. 32, figs. 44-46, in part and not including pi. 24, fig. 39). 

 1903. Cadulus jeffreysi, Dall, Bull. 37, U. S. Nat. Mus., p. 76 (not of Montero- 

 sato, 1875). 



The shell is very small, rather stout, with its greatest diameter 

 about median and not marked by a local swelling, and with a large 

 oblique anterior aperture having a rounded peristome. The apical 

 orifice is tliree-fourths the size of the larger aperture and is somewhat 

 constricted. The convex outline forms a regular arch, slightly 

 flattened anteriorly and rendered slightly concave just back of the 

 apical opening. The concave side is almost a straight line, with a 

 slight convexity at the equator. The lateral outlines are quite 

 straight as the shell is not flattened and the apertures are of so nearly 

 equal size. No apical features are observable. 



The type. Cat. No. 38963, U.S.N.M., measures— length, 2.75 mm.; 

 diameter, 0.75 mm.; anterior aperture, .50 mm.; apical aperture, 

 0.4 mm. It was obtained at the U. S. B. F. Station 871, off Marthas 

 Vineyard, in 115 fathoms, bottom of mud and fine sand, temperature 

 49° F. 



A critical comparison of these little shells with the many specimens 

 in the Jeffreys collection under the names given m the synonymy 

 above convinces me of the propriety of separating them specifically. 

 The many lots in that collection named Cadulus' jeffreysi include two, 

 if not tliree, seemingly distinct species, one of which, from northern 



