108 BULLETIN 111, UNITED STATES NATIONAL MUSEUM. 



The apical features are not well shown on the unique specimen, but 

 dorsal and ventral widely chipped out notches are indicated. Meas- 

 urements are: 



Length, 17.5 mm.; diameter, 2.8 by 2.5 mm.; anterior aperture, 

 2.1 by 2 mm.; apical aperture, 1.4 mm. 



The type is in the Museum of Comparative Zoology, Cambridge, 

 Cat. No. 7741, and was dredged by the Blake at United States Coast 

 Survey Station 230, off St. Vincent, West Indies, 464 fathoms, bottom 

 of fine sand, temperature 4H° F. There are no specimens in the 

 United States National Museum. 



This species was referred by Doctor Dall and later by Pilsbry and 

 Sharp to Verrill's Cadulus spectahilis. It is closely related to that 

 species, but the shell is smaller and more curved and has a larger apical 

 orifice and smaller section at its equator. The extreme anterior posi- 

 tion of the equator makes the resemblance the more striking. In 

 this respect it also resembles C. poculum, but it has, on the other hand, 

 a much larger shell. It is also larger than C. acqualis, another of the 

 large Caduli of this same group. The ivory white color may be no 

 more than an individual feature, but if it proves to be a constant one 

 it might be accepted as a specific character of some importance. 



CADULUS (PLATYSCHIDES) POCULUM Dall. 



Plate 17, fig. 8. 



1889. Cadulus poculum Dall, Bull. Mus. Comp. Zool., vol. 18, p. 429. 

 1889. Cadulus poculum Dall, Bull. 37, U. S. Nat. Mus., p. 76. 

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

 17, p. 172, pi. 33, figs. 56, 57. 



The shell is slender and strongly arcuate, especially in the posterior 

 portion; it has a rather gibbous swelling, with an obtuse angled 

 equator, especially noticeable on the convex side, at a point only 

 about one-fifth the distance from its extremely oblique anterior aper- 

 ture. Between the equator and the anterior aperture the shell is very 

 conspicuously flattened "like the mouth of a whistle." The convex 

 side shows a regular and rather strong curve to the point of maximum 

 caliber at the obtusely angled equator, but thence on the anterior 

 aperture along the flattened compressed surface of the shell it describes 

 a straight line, even across the aperture to the opposite side. The 

 concave side shows a strongly curved outline throughout its posterior 

 half, but a less curved one anteriorly with a point of slight convexity 

 at the swelling just back of the aperture. From the equator the 

 shell posteriorly is slightly flattened, slender, and evenly tapering to 

 a small apical orifice. The anterior aperture is very oblique (quite 

 45°) and transversely elliptical. The apical features are not clearly 

 shown in the few museum specimens, but lateral projections from the 

 margin of the orifice would indicate characters similar to those of 

 Cadulus pandionis; that is, shallow circular cuts extending across the 



