174 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



article is about twice as long as the third; the fifth is a little longer than 

 the fourth. The flagellum is composed of sixteen articles. The second 

 antennae extend almost to the posterior margin of the first thoracic 

 segment. The frontal lamina is round in outline at the base, which is 



o 



ventrally situated, not directed anteriorly. The maxilliped has a palp 

 of five articles. . 



The first, fourth, fifth, and sixth segments of the thorax are longer 

 than the others. The epimera are distinct on all the segments with 

 the exception of the first. They are narrow plates with the post- 

 lateral angles acute. A distinct carina extends obliquely from the 



post-lateral angle to the middle of 

 the side adjacent to the segment in 

 the last three epimera and to the 

 inner an tero- lateral angle in the 

 first three epimera. 



All six segments of the abdomen 

 are distinct. The lateral parts are 

 not separated from the dorsal por- 

 tion. The sixth or terminal seg- 

 ment has the sides converging to an 

 extremity, which is truncate or but 

 slightly excavate and about half as 

 wide as the base, 3 mm.: 7 mm. 

 The posterior margin is crenulate. 

 The branches of the uropoda are 

 about equal in width; the outer one 

 is rounded posteriorly; the inner 

 one is obliquely truncate, the inner angle rounded, the outer one being 

 more acute. The branches of the uropoda are somewhat crenulate 

 and furnished with spines. The basal article extends two-thirds the 

 length of the last abdominal segment. 



The first three pairs of legs are prehensile, the last four pairs ambu- 

 latory. The propodus of the second and third pairs is furnished with 

 a linguiform process at the distal end; the carpus has one very small 

 and inconspicuous spine; the merus also has five small inconspicuous 

 spines. rt 



FIG. 155. 



x 27|. 



CRENULATA. a, MAXILLIPED. 



b, SECOND LEG. x 9|. 



o For description of the young of the second and third stages see Sch iced te and 

 Meinert, Nat. Tidsskr. (3), XII, 1879-80, pp. 344-346. 



