68 BULLETIN OF THE 



The specimen measured was the hirgest, and that which had the greatest 

 apical angle ; the alternative measurements are from an adult, but more slen- 

 der specimen. Considering the number obtained, the variability was perhaps 

 not greater than might have been expected. 



P. (Drillia) Verrillii n. s. 



Shell resembling D. olcacina on a very small scale ; white, with a large 

 white, smooth, inflated nucleus ; whorls six or seven, rounded, polished, trans- 

 lucent waxen whitish ; transversely sculptured by twelve to fourteen rounded, 

 stout, strongly raised ribs extending forward from the notch-band to the su- 

 ture, or on the last whorl to its anterior third ; on the last half of the last turn 

 evanescent ; suture appressed ; lines of growth evident ; spiral sculpture, none 

 visible ; a decided callus with a groove behind it on the pillar and body whorl ; 

 notch, as usual in the adult, rather deep ; aperture rather wide behind, and 

 shaped as in D. oleacina. Lon. of shell, 5.5 ; of last whorl, 3.0 ; of aperture, 

 2.0. Max. lat. of aperture, 1.0 ; of shell, 1.75 mm. 



Station 19, 310 fms. 



This pretty little species seems quite distinct from any of the others, and 

 unlike any of the known Northern forms. This and the three previously de- 

 scribed species form a little group similar in general character, yet distinct in 

 detail, but requiring close and careful inspection. 



p. (Drillia) peripla n. s. 



Shell small, rough, dark-colored (normally?), acute, nine-whorled ; nucleus 

 and two and a half nuclear whorls yellowish, with sculpture reticulated 

 by raised revolving lines, and lines waved backward from before and behind 

 a point on the periphery ;* remainder of the shell transversely sculptured by 

 twelve or (on the last whorl) fourteen rounded ribs, which start at the ante- 

 rior border of the band, where they are roundly shouldered, and continue 

 somewhat obliquely to the suture, or, on the last whorl, to the anterior third, 

 narrowing as they go ; beside these, the lines of growth are well exhibited 

 and the notch-band is ornamented by distinctly raised, transverse, backwardly 

 concave plications, which extend across it, about nine in the space of a milli- 

 meter, with wider interspaces ; .spiral sculpture consisting of (on the smaller 

 whorls) three to (on the last whorl) about nine raised rounded riblets, the first of 

 which is just in advance of the band, and between every pair of which are two 

 (or in rare cases) three much finer threads ; the primary threads are a little 

 swollen where they cross the transverse riblets, the secondary threads not so ; 

 toward the anterior end of the canal the threads become uniform in size and 



* This peculiar sculpture of the nuclear whorls is noted by Verrill in one of his 

 Plcurotomcllce, and lias been described several times in this paper. It was described 

 and figured as a mature form by D'Orbigny under the name of Sinusigera. Cf. 

 Sagra, Moll. Cuba, Atlas, PI. XXIII. figs. 7-9. 



