Die, KOONSIA. 
K. opesa Verrill. Pl. 74, fig. 94. 
Body large, stout, broad, with a large, swollen back, smooth and 
white in the preserved specimens, and defined by the mantle-edge, 
which forms a rim along the lateral and posterior borders. Head 
large and broad, with two short, flat, posteriorly grooved, anterior 
tentacles, one at each corner; the anterior mantle-border runs be- 
tween them, and supports a row of small papille. Posterior tentacles 
short, stout, flattened, ear-like, with the outer edges incurved, form- 
ing a large groove. Proboscis very large, retractile, purple at the 
end, showing when extended, the very broad radula covered with 
very numerous sharp, hooked teeth, in many long curved rows. 
Foot broad and rounded anteriorly, with small auricles; long 
tapered, and acute posteriorly, extending some distance beyond the 
mantle; a conical papilla near the tip above; under side, near the 
end, with a narrow, elongated, depressed, glandular area, surrounded 
by a raised border; this is sometimes tinged with bright-red, in 
alcohol; the rest of the foot is usually tinged with chocolate-brown. 
Gill large, bipinnate, deep purple. (Verrill.). 
This species grows to a great size. One from station 939, was 
over 5 inches (128 mill.) long ; 4 inches (102 mill.) wide; and about 
2 inches (50 mill.) high, even after preservation in alcohol. 
Off Martha’s Vineyard, in 216-258 fathoms; Off Delaware Bay 
in 312 fathoms. 
Koonsia obesa VERRILL, Trans. Conn. Acad., v, p. 545, (July, 
1882); Rep. Commissioner Fish and Fisheries for 1883, Appendix 
D; poll, pls 23; tedi07- 
The figure represents the dorsal aspect, two-thirds natural size. 
K. morosa Bergh. PI. 54, figs. 90, 91, 92, 93, 94. 
Described from a single, very flaccid specimen, measuring 15 mill. 
long, 10 wide, 5°5 high. In form and dimensions it resembles P. 
aurantiacus. Margin of the mantle equal in width to that of the 
foot, 1 mill.; tail 2 mill. long; gill 4°5 long, free for over half its 
length, with 15 pinnules. Anus below the posterior extremity of 
the gill-insertion; renal and genital pores as in Pleuwrobranchus; at 
the end of the tail is an elongated gland. Color of the animal pre- 
served in alcohol is grayish, with a quantity of violaceous dots, 
scattered principally toward the edges of mantle and on the rhachi- 
dian part of the gill. 
