BALCH: LIST OF MARINE MOLLUSCA. 
151 
kindness in showing me his unpublished sketches of P. emertonii 
has allowed me to satisfy myself of the very different appearance of 
the two. Were it not for the great similarity of the dentition P. 
davenportii would seem entitled to generic distinction on the ground 
of the very different gills and the uncovered foot. No armature of 
the penis could be made out in sections, but this was perhaps owing 
to poor preservation. 
Specimens of P. davenportii were first taken on August 16 from 
hydroids on lobster-pot lines, and again about two weeks later- 
appeared in jars of stones, weeds, hydroids, etc., which had been: 
dredged in about 3 fath. 
COEAMBIDAE. 
Corambella gen. nov. PI. 1, figs. 12-15. 
Form Corambe-like (c/. Bergh, ’71 and ’92, and IT. Fischer, ’91), but more 
convex and proportionately longer. Notaeum as in Corambe, but without 
the anal notch. Rhinophores not foliate laminate or branched; tapered, 
retractile, with sheaths. Anus and gills as in Corambe, viz.: anus median, 
posterior, between the foot and the gill plates, which lie posteriorly on either 
side between foot and notaeum, completely hidden by foot in life. Genital 
papilla anterior, left side, hidden in life. Jaws and pharyngeal bulb without 
plates or other armature. Radula large, no rhachidian tooth; pleurae large, 
twisted, the median ends bent up and back in a heavy hook; uncini five, stout, 
claw-shaped. Formula 5-1-0-1-5. 
This genus is erected to contain a form closely allied to Cor¬ 
ambe sargassicola Bergh and C. testudinaria H. Fischer, but 
not to be included within that genus because of the lack of the anal 
notch and the different dentition. The anal notch is by Bergh 
made a family character, yet no doubt the present form must fall 
within his Corambidae. 
Corambella depressa sp. nov. 
Form Doris-like, much flattened in life, broadly rounded in front and bluntly 
tapering posteriorly. Length 5 mm., breadth 3 mm. Color sometimes dull 
brown with gray irregular reticulation, but occasionally rather bright and 
conspicuous, when a translucent dull blue ground-color is indistinctly, coarsely, 
and irregularly blotched with dirty green or greenish brown and irregularly 
scattered with small black spots, the pattern darker and closer toward the 
center, producing a radial effect. Between the blotches in every direction run 
very conspicuous opaque yellowish white lines like the borings of larvae under 
t 
