NO. 2 NEW TURRITID MOLLUSKS BARTSCH 21 



tuberculated cords, the third one almost falHng into the suture, being 

 appressed to the cord at the summit of the succeeding turns. These 

 remain inconspicuous on the succeeding turns, while the other two 

 occupying the middle portion of the shell become decidedly pro- 

 nounced. The cord at the summit forms an abrupt sloping shoulder, 

 and the space between this and the first strong spiral cord constitutes 

 the sulcus marking the posterior channel of the shell. In addition 

 to these spiral cords the cords themselves and the spaces that separate 

 them are marked by strong spiral threads. This is also true of the 

 sulcus at the summit, the base, and partly so of the columella. The 

 axial sculpture consists of very heavy, broad, low, rounded ribs which 

 are about twice as wide as the spaces that separate them. These ribs 

 are rendered nodulose by the two strong spiral cords. They are also 

 marked, as well as the intercostal spaces, by slender lines of growth 

 that extend over the entire surface of the shell. Of these ribs, 12 

 are present on all the whorls. Suture slightly constricted. Periphery 

 well rounded. Base short, marked by three strong spiral cords. Colu- 

 mella moderately long, slightly curved and marked by nine strong 

 spiral cords, between and on which slender spiral threads are present. 

 Aperture moderately long, channeled posteriorly and anteriorly. Un- 

 fortunately, the outer lip is fractured in the unique type so that it is 

 impossible accurately to describe this, and the shell is not sufficiently 

 mature to have differentiated the heavy varix behind the aperture 

 characteristic of the group. The inner lip constitutes the heavy callus 

 that extends upon the parietal wall. 



Type. — The type, U.S.N.M. no. 429401, has 11.7 whorls and mea- 

 sures : Length, 26.6 mm ; diameter, 7.4 mm. It was dredged at station 

 67 in 180 to 280 fathoms between latitude i8°3o'i2" N., longitude 

 65°45'48" W. and latitude i8°32'i8" N., longitude 65 "46' 12" W. 



This species is easily differentiated from Compsodrillia tristicha by 

 the fact that only two of the strong spiral keels are apparent on the 

 whorls. 



COMPSODRILLIA NANA, n. sp. 



Plate 6, figs. 1-3 



Shell small, elongate-conic, yellowish white. The first one-half nu- 

 clear turn well rounded, smooth, the last half marked by a few rather 

 distantly spaced, slightly protractively slanting axial riblets. Post- 

 nuclear whorls well rounded, the first marked by three slender spiral 

 cords, of which the anterior two increase more rapidly in size than the 

 first one, which remains rather feeble. The summit of the whorls is 



