MUSEUM OF COMPARATIVE ZOOLOGY. 63 



Station 43, 339 fins. 



A modest and distinct little species, remarkable for its stout obtuse and 

 unusually large nucleus. 



P. (Drillia) exasperata n. s. 



Shell yellowish-white, with a dull surface, except for the glassy and translu- 

 cent nucleus, slender, thin, eight- whorled ; nucleus thin, inflated, the (nuclear) 

 first two whorls polished, smooth, and free from sculpture, passing abruptly 

 into the dull and lustreless surface of the adult shell ; for the remainder, the 

 transverse sculpture consists of Bubequal ribs, largest on the periphery, smaller 

 toward the sutures, which they reach above and below, the track of the notch 

 not being marked by a flattened band, as is generally the case ; there are about 

 eleven of these to a whorl, on the last whorl they are less pronounced, and 

 become obsolete toward the anterior third of the whorl, where the lines of 

 growth are particularly conspicuous ; the completion of the adult aperture is 

 marked by a particularly large rib or swelling of the margin, which becomes 

 more conspicuous in case the shell continues to grow; in the older part of the 

 shell the ribs are continued in the same line from whorl to whorl, in the 

 last whorl and a half they become alternate or irregular ; the revolving sculp- 

 ture consists of (on the smaller whorls i two or three to (on the last whorl) 

 sixteen flattened raised bands, with wider interspaces, which are much more 

 marked, or even knobby, on the smaller whorls where they pass over the trans- 

 verse ribs', gradually become more uniform, and, on the last whorl, are nearly 

 as well defined between the ribs as on them ; nine of those on the last whorl 

 are crowded together on the anterior third, the rest spread over the body of the 

 whorl; there are hardly any traces of revolving striation; notch deep, but not 

 producing a band ; margin of the aperture thin, the outer lip produced for- 

 ward, a slight deposit on the body and pillar ; columella nearly straight, 

 slightly shorter than the rather' wide, somewhat recurved canal ; sutures 

 appressed, sinuous over the ends of the transverse ribs ; aperture less than one 

 third of the shell. Lon. of shell, 9.5 ; of last whorl, 5.0 ; of aperture, 3.0. 

 Max. hit. 3.5 nun. Den. about 27°. 



Off Cape San Antonio, 1002 fms. 



A rough-looking little shell, with somewhat the sculpture of a Ccrithi<>: 



P. (Drillia?) leucomata n. s. 



Shell more or less translucent white, short-fusiform, thin, polished, ten- 

 whorled; nucleus thin, very minute, inflated, clear transparent brown, with a 

 shining surface ; succeeding to it are three nuclear whorls, whitish brown, 

 smooth, bul nol shining like the nucleus. Bubinflated, and with a sharp, strong. 

 peripheral keel ; succeeding whorls marked by a strongly denned broad band 

 extending from the Buture more than hall-way over the whorl, descending 

 steeply to the periphery, where the keel of the nuclear whorls is continued a- 



