90 BULLETIN OF THE 



in the young, rounded in the adult ; the outer lip expanded and thickened 

 concave behind, basally produced and curving into a distinct but not producefl 

 canal, which opens to the left ; on the other side the outer lip is continuous 

 with a thin but distinct callus, which is twisted over the very short and incon- 

 spicuous pillar ; the reflected edge of this callus is not adherent to the pillar, 

 and there is a perceptible chink under it, or more properly above it ; the aper- 

 ture is subovate, pointed before and behind. Lon. of shell, 16.0 ; of last whorl, 

 3.62 ; of aperture (from point to point), 2.5. Max. lat of shell, 3.0 ; of ap- 

 erture, 1.75 mm. 



Station 2, 805 fms. ; Barbados, 100 fms. ; and numerous other localities. 



A very pretty, and apparently a very common species, which, except in its 

 attenuated apex has quite a general resemblance to Lovenella metula Sars of 

 Northern European shores. From Gerithium (Bittium) cylindricum Watson 

 (Australia) it differs in its color and in its non-convex outlines, and in having 

 four instead of three prominent spirals and many more whorls ; it has a larger 

 number of series of tubercles than C. (Bittium) gemmatum Watson from Setu- 

 bal, and two more spirals ; it is much larger than G. {Bittium) figrum Watson, 

 and of all Watson's species is perhaps most like G. (Bittium) mamillanum from 

 Pernambuco ; but the details of sculpture, size, and number of whorls diff"er 

 quite sufficiently. 



Bittium (?) Yucatecanum n. s. 



Shell stout, solid, conical, waxen white or grayish, with about eight rather 

 rounded whorls ; spiral sculpture of four (afterward five) revolving, flattened 

 threads, with about equal interspaces ; the first is about its own width, or a 

 little more, in advance of the suture ; the second, about the same distance in 

 advance of the first, is equal to it in size ; both are smaller than the third, 

 which is the largest and most prominent of all, and gives a subcarinate appear- 

 ance to the whorl, or than the fourth, which is about midway in size between 

 the second and third ; on the later whorls a fine thread appears just behind the 

 suture which it crowns, and on the last turn forms the periphery of the base, 

 within which appear two or three others, growing fainter toward the canal ; 

 the shell is also covered with microscopic revolving striiB ; the transverse 

 sculpture consists of fourteen to eighteen faint plications or riblets, which 

 appear to pass under and in so doing to undulate the spirals, especially the 

 third and fourth ; in some specimens these undulations may appear tubercu- 

 lar, but they do not in the one under consideration ; the sutural thread is not 

 undulated, and the reticulation is confined to the sides of the whorls, the base 

 being crossed only by rather strong lines of growth. Base rounded ; pillar 

 straight, rather slender, short, without any marked callus ; aperture rounded ; 

 outer lip thin, notched by the spirals, with a faint emargination near the pillar, 

 but no well-marked canal ; the nucleus is mostly broken away, but seems to 

 have been helirironn, turned half over, and partly immersed. Lon. of shell 

 8.0 ; of last whorl, 3.5 ; of aperture, 2.0. Max. lat. of shell, 3.0 ; of aperture, 

 1.5 mm. 



