MARINE ISOPODA OF NEW ENGLAND, ETC. 353 



The body is rather raore robust tlian in the last species, the length 

 being only about two and a half times the breadth, and is peculiarly 

 marked above by depressed and mostly curved lines, varying in length 

 but mostly short, and confined principally to a region on each side of 

 the median line and extending across the head but not the jjleon. 



The head is broadly emarginate in front, with a median notch, and its 

 anterolateral angles are prominent. The eyes are at the widest part of 

 the head, and are strongly convex. The posterior outline of the head is 

 nearly in the form of three sides of a hexagon. The antennulse attain 

 about the middle of the fourth antennal segment. The antennce are 

 about one-half as long as the body. The first two antennal segments 

 are short and apparently articulated so as to admit of but little motion ; 

 the third segment is a little longer than the first two taken together, 

 and is the largest of the antennal segments in diameter; the fourth 

 segment is somewhat longer than the third, and the fifth or last pedun- 

 cular segment is the longest, and is followed by a flagellum, a little 

 shorter than the peduncle and composed of about fourteen segments. 

 The last three peduncidar segments of the antennse are somewhat 

 bristly hairy. The maxillipeds are nearly as in the preceding species. 

 The outer maxillae are destitute of the elongated, pectinate setae found 

 in that species. 



The thoracic segments vary but little in length measured along the 

 median line, but the fifth, sixth, and seventh are slightly shorter than 

 the preceding ones, and this difference is still greater measured along 

 the margins of the segments, where the first is longest, the next three 

 about equal, and the last three shorter. The legs are robust, the first 

 pair shortest, and all more or less bristly hairy. The lateral margins of 

 the segments are much less rounded than in S. nodulosa. 



The pleon is short, the length being scarcely greater than the breadth 

 at base; above, it is nearly smooth, the impressed Unes, so conspicuous 

 in the lateral region of the thorax, being continued for but a slight dis- 

 tance upon its surface. The incision at each side near the base is con- 

 tinued upward and forward by a depressed line on each side ; the lateral 

 margins are gently convex to near the tip, which is distinctly bicuspid. 

 The basal plate of the operculum is traversed obliquely by a longi- 

 tudinal ridge on the external surface, and is rounded in front, slightly 

 narrowed behind, and bears a short, triangular, terminal plate, its length 

 being but little greater than its bi'eadth. 



Length 15.5"""; breadth 6'"™. Color in alcohol grayish, with white 

 cloudings. Lockington says: "When recent, the coloration of this spe- 

 cies is very beautiful, consisting of red cloudings on a lighter ground." 



There seems to be no doubt in regard to the synonymy of this species 

 as published by Streets and Kingsley, adopted by the writer in a previous 

 publication, and given above. 



The only specimens that I have examined were two, brought from the 

 Grand Banks !, in the summer of 1879, by Mr. Charles Buckley, of the 

 23 F 



