550 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



gated lamellse, similar in shape to the uropoda, and are placed close to 

 the lateral margins of the seg'ments on the underside, so that in a dor- 



FiG. 596. — Argeia pugettensis. a, Dorsal view of immature female, b. Ventral view of 

 SAME. X 14^. (Second post-larval stage.) 



sal view they appear attached to the lateral margins of the segments. 

 They form a border around the abdomen. The inner branches are 

 rounded, sac-like bodies, usually decreasing in 

 size f I'om the iirst to the last. 



There are five pairs of incubatory lamelLT? 

 which do not completely inclose the marsupial 

 pouch. The distal part of the first pair has the 

 posterior margin not produced in a lobe. 



The legs are all prehensile. The basis of all 

 seven pairs is provided with a high rounded 

 carina. 



The male is narrow, elongate, symmetrical 

 in outline, 5i mm. long and li mm. wide. 

 Eyes are present. The anterior margin of the 

 head is widely rounded. The first pair of an- 

 tennae are composed of three articles. The 

 second pair are composed of four articles. All 

 the thoracic segments are distinct. The lateral 

 margins are straight, but not contiguous. All 

 seven pairs of legs are prehensile. The seg- 

 ments of the abdomen are coalesced in a single segment, narrower 

 than the thorax, which tapers to a point. It is 1 mm. wide and 1^ 

 mm. long. There are no uropoda and no pleopoda. 



The individual described was found in the branchial cavity of JVec- 

 tocrangon lar. 



Pig. 697.— Argeia pugetten- 

 sis. (Cryptoniscan stage.) 



