STREETSIA CARINATA. 87 



4. Streetsia carinata, n. sp. 



PI. Ill, fig. 1315, PI. IV, fig. 1 and 2; and p. 34, fig. 58. 



Diagn. The head is as long as the peraeon and the first pleonal seg- 

 ment together; the rostrum is not fully as long as the rest 

 of the head. 



The perceon is dorsally carinated. 



The under margin of the carpus of the first pair of perceopoda is 

 strongly serrated, with short, broad teeth, and has the hind 

 corner projecting into a long sharp tooth; the hind margin 

 of the metacarpus is smooth, and is longer than the under 

 margin of the carpus ; the dactylus is more than half as long 

 as the metacarpus. The second pair are almost cheliform, 

 with the front margin of the carpal process smooth and ending 

 into a broad sharp tooth; the hind margin of the metacarpus 

 is armed with a few short, broad teeth, and is about as long 

 as the front margin of the carpal process with the apical 

 tooth; the dactylus is more than half as long as the meta- 

 carpus. The fourth pair are a little longer than the third. 

 The lower hind corner of the femur of the sixth pair is 

 produced downwards into a long rounded process, which 

 reaches far beyond the apex of the genu. The femur of 

 the seventh pair is not half as long as that of the sixth, 

 and is much shorter than all the following joints together. 



The pleon is dorsally carinated; the lateral parts of the seg- 

 ments are rounded behind. 



The last coalesced ural segment is about a third part longer 

 than broad, and is quite as long as the telson. 



The peduncle of the first pair of uropoda is shorter than the 

 last coalesced ural segment, and is as long as the inner 

 ramus. 



The telson is lanceolate, and is about three times as long as 

 broad. 



Streetsia carinata is easily distinguished from the other spe- 

 cies by the perseon and pleon being dorsally carinated, and the femur 

 of the seventh pair of perasopoda considerably much shorter than all 

 the following joints together. 



