168 



Miss H. Richardson on the Isopods of the 



flagellum of twelve joints, extend almost to the posterior 

 margin of the first thoracic segment. 



The last four thoracic segments Fig. 5. 



are each a little longer than any of 

 the first three. The epimera are 

 narrow, with rounded post-lateral 

 angles. 



The five abdominal segments are 

 of equal length. The terminal seg- 

 ment is subtriangular, with truncate 

 extremity ; its posterior margin is 

 crenulate and fringed with iiairs. 

 The iiropoda exceed slightly the 

 length of the abdomen. The inner 

 branch is about twice as wide as the 

 outer branch; is obliquely truncate ^l^tia Leco,itii(\)m&). x 2. 

 and crenulate. The outer branch is 



narrow, rounded posteriorly, and smootli. B^th brandies are 

 fringed with hairs. 



The legs are long and slender. Five spines are present on 

 the merus of the prehensile legs. The gressorial legs are but 

 slightly spinulose. 



Two specimens examined were collected at Monterey Bay, 

 California, by Mr. Heath. 



The description of this species of ^ga by Dana as ^ja- 

 cylla Lecontii was from a young specimen *. The individual 

 sent us is thought to be the adult form, and differs from 

 Dana's description f of the young individual in the crenulated 

 posterior margin of the terminal segments, in the truncated 

 inner branch of the uropoda, and in the addition of two joints 

 to the length of the flagellum of the second pair of antennae. 



7. RociNELA, Leach. 



Analytical Key to the Species o/ Rocinela. 



o. Flagellum of second pair of antennae 

 with fourteen to sixteen joints. 

 h. Propodus of prehensile legs with 

 two to four spines. 



* Schiodto and .Meinert rej^ard ^(janjlla, Dana, a-s synonymous with 

 Mga, and remark that Dana'.^ specimen, by which tlie genus .-EiiacyUa 

 was instituted, wa^ a young .Kija. See • Naturhi*toii-.k Tidsskrift,' xii. 

 1879-80, p. 33i. See also Liitken, Vid. Medd. Naturh. For. J8(X), 



p. 180. 



t There are no specimens of tlie young in the National Museum. 



