454 .1 . K VtrrW — C atob of Jf'/rine MoUusco. 
The color of all the specimen* is delicate, pale, yellowish brown, 
or salmon, uearly uniform throughout, except for the darker brown- 
nucleus. 
The tentacle- are tapered, with a -welling on the outer -ide. near 
the ba-e. but have no eyes: the peni- is very large and loug, round, 
nearly cylindrical, except near the tip. where it tapers; iu alcoholic 
specimens it is uearly a- thick as the neck, from which it arisen 
The uncini of the odontopbore are long-lanceolate, acute, with a 
tooth on one ride, near the middle, but without terminal barbs; 
basal proces- ( manubrium i large, somewhat bilobed. 
An immature female has the whorls somewhat more convex and 
more evenly rounded, or less shouldered, and the trausverse ribs 
-mailer and les- elevated than in the example originally described, 
which was a male, (fig. 9). In this female, the -pire is also slightly 
less acute, but otherwise the shell does not differ in the two sexes. 
The length of thi- -pecimen is 1 3* ; greatest breadth. 6; canal and 
body-whorl, in front, 9*5. The original male is 9 long, 11*5 
broad; canal and body-whorl, 15 long. 
This shell is much thinner and far more delicate than the two fol- 
lowing -pecies, from which it also differ- in having a much deeper 
sinus, more convex whorls, a narrower canal, and much finer sculp- 
ture. 
Gulf of Maine, 110 fathoms ($. 89. Bacbe), 1872 ; 105 and 1 10 fath- 
oms (:8. 51. 54, B./, 1874 : 85 fathoms (S. 1*9), 1878: off Cape 
Cod. 96 fathoms >. 37*), 1879. 
Pletirotomella Aga-ssizii Vcmii i -mith. 
Plemraloma ( PUm/vtomtUd) A<fu«*izii Terrill k srniih. Amer. Joura. Set. xx p. 394. 
for Xov_ Is- (published Oct. 25> * : V errill. Pnoc. r. >. Xat. Mus.. iiL p. 3f>7. 
1880. 
Plate LYIL FHiCKES 3, 3a. 
Shell rather large and -olid : whorls eight or nine, convex, angu- 
larly shouldered, with sixteen to eighteen thick, rounded, oblique 
ribs, separated by concave interspaces; the ribs do not extend above 
the shoulder, leaving a rather broad, flattened, or concave, subsutural 
band, which is covered by fine, raised, revolving lines, more or less 
decussated by distinct lines of growth, and by many curved riblet-. 
running down from the -uture: the revolving line- become Wronger, 
more elevated, and wider apart below the shoulder, and cross the 
rib- as well a- their intervals: toward the base of the canal the ribs 
