484 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. xxxv. 



converging to a pointed extremity ; eyes entirely absent. First pair 

 of antennae with the first two articles of the peduncle subequal ; third 

 article about one and a half times longer than 

 either of the two preceding. Flagellum com- 

 posed of four articles on one side and five on the 

 other; first article minute; second and third 

 elongate, the third being longer than the sec- 

 ond; fourth half as long as third; fifth half 

 as long as fourth. First antennse extend to end 

 of peduncle of second pair. Second pair of an- 

 tennas with first article of peduncle long; second 

 article half as long as first; third article almost 

 as long as first ; fourth about one and a half times 

 longer than third; flagellum, composed of seven 

 articles, extends to tip of mandibles. Mandibles 

 narrow and elongate, extend one-third of their 

 entire length beyond extremity of rostrum. 

 fig. i.— bathygnathia About one-third the distance from the base, on 

 the outer margin, is a prominent,— acute tooth. 



margin, is 



Tip of mandible bent and directed inward ; man- 

 dibles narower from a point beginning about op- 

 posite tip of rostrum and converging from that 

 point to the acute extremity. 



All seven segments of the thorax free; first 

 short, about half as long as the two following 

 which are subequal, and equal in width to those 

 succeeding; fourth segment equal in length to 

 second and third together; fifth longest, about 

 one and a fourth times longer than the fourth; fig. 2.— bathygnathia 

 sixth about equal in length to the fourth ; seventh curvirosteis. man- 

 extremely short, not longer than the segments of 



the abdomen and not as wide. The second and 

 fourth segments have the lateral margins pro- 

 duced at the anterior portion in small angular 

 processes. 



First four segments of abdomen equal in 

 length, with their lateral margins produced in 

 triangular processes directed posteriorly; fifth 

 segment about one and a half times longer than 

 the preceding; terminal segment triangular, the 

 sides converging to a long, narrow, pointed ex- 

 tremity. Branches of uropoda similar in shape, 

 with the sides converging to a rounded extremity ; 

 outer branch shorter than the inner, which extends beyond the tip 

 of the terminal abdominal segment. The outer branch does not 

 extend beyond the extremity of the last abdominal segment. 



Fig. 3. — Bathygnathia 

 curvirostris. first 

 leg of male. 



