570 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



from the last by an incision reaching' about half way to the median line, 

 Last segment entire, ovate behind, and cuspidate. The style on the 

 second pair of branchial plates in the male is slender, surpasses the 

 lamina?., and reaches the middle of the terminal cilia ; it is obliquely 

 truncated at the end. 



Many of the specimens, especially the smaller ones, are furnished 

 with a row of prominent tubercles along the back, and sometimes with 

 lateral rows. 



Length, 10-25 mm ; breadth, 3-7.5 mm . 



Long Island Sound to Bay of Fundy. 



Erichsonia filiformis Harger. Plate VI, fig. 26. (p. 316.) 



'Slenosoma filiformis Say, loc. cit., p. 424, 1818. 



Small, slender, and nearly linear in outline. Antennula? not quite 

 attaining the fourth segment of the antenna?, which are six-jointed, and 

 more than half as long as the body, with the first segment short, second 

 and third increasing in length, last three segments about equal; head 

 elevated between the eyes, where it is surmounted by a bifid tubercle ; 

 first and second thoracic segments with a lateral salient angle behind 

 the evident angulated epimera; third and fourth segments with their 

 lateral borders emarginate, and the epimera concealed or rarely visible 

 from above at the einargination ; last three thoracic segments angulated 

 in front of the epiuiera, which are also angular. This arrangement, 

 especially in the smaller specimens, gives the appearance of fourteen 

 serrations on- each side of the thorax. There is a row of tubercles 

 along .the median line. Abdominal segments consolidated into a 

 single piece, which is furnished with a divergent tooth on each side 

 near the base, and is expanded and obtusely triangular at the apex. 

 The style on the second pair of branchial plate's in the male is strong 

 and curved, surpasses the cilia, and is acute and sharply serrate near 

 the end. 



Length, 5-9 mm . 



Vineyard Sound to Great Egg Harbor, New Jersey. 



Erichsonia attenuata Harger, sp. no v. Plate VI, fig. 27. (p. 370.) 

 Body smooth, narrowly linear in outline. Antennula? slightly sur- 

 passing the second segment of the antenna?, which are more than half 

 the length of the body, and have the last segment longest. Head exca- 

 vated in front; eyes small, black, prominent; first thoracic segment 

 short; second, third, and fourth segments about equal in length, twice 

 as long as the first; third segment broadest, last three segments gradu- 

 ally decreasing in length. Epimera visible from above only in the last 

 two or three segments, but the sutures are evident, except in the first 

 segment, and their position moves gradually from the anterior portion 

 of the segment in the second to the posterior in the seventh segment. 

 Abdominal segments consolidated into a single piece, which is slightly 

 dilated laterally near the base, and obtusely triangular at the tip. The 



