MARINE ISOPODA OF NEW ENGLAND, ETC. 407 



differing little in the sexes, hardly surpassing the peduncle of the anten- 

 nulaB in the males, with a short three or four jointed flagellum bear- 

 ing a few hairs near the tip. The inaxillipeds (pi. XI, fig. lib) have 

 a quadrate basal segment, somewhat emarginate externally for the 

 subtriangular external lamella, and bearing a single suboval terminal 

 segment, or palpus, somewhat truncate and ciliated at the tip. The 

 inner maxillae (pi. XI, fig. 71c) are five-toothed, one tooth being strong 

 and terminal and the other four lateral. The mandibles bear a single- 

 jointed palpus. 



The thoracic segments are subequal in length except the last, which 

 is but little over half as long as the others, though broader behind than 

 any of them. They are slightly narrower than the head and margined 

 laterally with a somewhat raised ridge. The third, fourth, and fifth have 

 an elongate oval depression on the median line near the anterior margin. 

 The first pair of legs (pi. XI, fig. 72) have the segments well separated, 

 the carpus nearly equilaterally triangular, the propodus moderately thick- 

 ened, and the dactylus strong and tipped with a stout claw; the carpus 

 and propodus are bristly on their palmar margins. The remaining pairs 

 of legs are slender and nearly equal in size. 



The pleon is about as long to the tip as the last three thoracic seg- 

 ments. The first five segments are consolidated along the dorsum, but 

 distinct at the sides. Each segment rises into a low broad tubercle on 

 each side of the median line. The last segment is about as long as the 

 preceding five, and is elongate-ovate, and obtusely pointed behind. The 

 basal plate of the uropods is about half as long as the telson; the 

 terminal or inner lamella is triangular-ovate, and about equals the 

 telson. The proximal or superior lamella is narrowly semi-ovate, 

 with an emargination on the upper side near the tip. The first pair of 

 pleopods (pi. XI, fig. lid) are shorter than the abdomen, and have the 

 outer plate semi-obovate and the inner shorter, with nearly parallel 

 sides. The second pair of pleopods (pi. XI, fig. 71e) bear, in the males, 

 a slender straight stylet, articulated below the middle of the inner 

 lamella and slightly surpassing it. The outer lamella is imperfectly 

 articulated near the middle. 



Length ll mm ; breadth 0.9 mm ; females about one-third smaller ; color 

 brownish and more or less mottled above, lighter beneath, margined with 

 translucent at the sides, extending on the sides of the head as far as 

 the eyes. 



This species is rare on the coast. It has been taken by the United 

 States Fish Commission, on muddy bottom, in Noank Harbor, Long 

 Island Sound ! ; off Watch Hill !, K. I., in 18 fathoms, sand ; and off Block 

 Island!, in 17 to 19 fathoms, sand, mud, and stones; at Waquoit, 

 Vineyard Sound!, in sand, at low water, September 8, 1871; in Casco 

 Bay !, sand and mud, from 9 fathoms, in 1873, and by Prof. A. E. Verrill, 

 at Grand Menan, in the Bay of Fundy ! in 1870. 



It is nearly related to and doubtless congeneric with Paranthura 



