222 KOONSIA. 



K. OBESA Verrill. PI. 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 papilla?. 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, p, 571, pi. 28, f. 107. 



The figure represents the dorsal aspect, two-thirds natural size. 



K. MOROSA Bergh. PL 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 Pleurobranchus ; 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. 



