ISOPODS OF NORTH AMERICA. 



455 



Fig. 507.— Janirop- 

 sis californica. 

 Anterior part 



OF BODY. V 27. 



JANIROPSIS CALIFORNICA Richardson. 



Janiropsis calif ornica Richardson, Harriman Alaska Exp., Crust., X, 1904, pp. 

 223-224; Proc. U. S. Nat. Mus., XXVII, 1904, i)p. ()()()-0fi7. 



Locality. — Sausalito, California. 



Body narrow, elongate; .surface smooth; coloi- uniformly whitish. 

 Head with a prominent rounded median lobe on tlu? anterior mar«-in: 

 lateral angulations rounded; lateral margins straight 

 and converging toward the base. Eyes black, distinct, 

 but small, and simple in structure. First pair of 

 antenme are composed of six joints and extend nearly 

 to the middle of the fifth joint of the peduncle of 

 the second pair of antetuuv. Second pair of antenna? 

 are about equal to one-thii'd the length of the body; the 

 flagellum is composed of nineteen or twenty joints. 



The first thoracic segment is but little wider than 

 the head; the margins are entire, lateral lobes rounded. 

 The second segment has the lateral margin straight, 

 with the epimeron showing slightly along the edge. 

 The third and fourth segments have the antero-lateral 

 lobe rounded, the posterior margin straight, with the 

 epimeron showing as a rounded lobe. The fifth, sixth, 

 and seventh segments have rounded lateral margins, with epimera 

 showing on the posterior part of the segments. 



Terminal segment rounded posteriorly with smooth 

 margins, and a median lol)e between the uropoda. 



Uropoda very short, about half as long as the ter- 

 minal segment. Branches about ecpial in length and 

 twice as long as the peduncle. 



Legs simple, ambulatory, similar in shape and size, 

 and bi-unguiculate. 



Only two good specimens, both females, were taken at 

 Sausalito, California, by Doctor Ritter and part3\ Two 

 imperfect specimens also are from the same locality. 

 "^ ''■ Until now the only other known species of this genus 



was J(nu'roj).sis hreviremus Sars." As that author has pointed out, this 

 genus difi^ers from J{(iiira^ to which it is very closely related, in the 

 much shorter uropoda; in the shorter second pair of antemue; in the 

 structure of the first pair of antenna?, which have the fiagellum com- 

 posed of onh- a restricted numl)er of articulations; in the structure of 

 the first pair of legs in the male, these being *" remarkably developed, 

 prehensile, much longer than any of the other pairs, with the carpal 

 joint fusiformly dilated;'" in the female, however, tliis pair does not 

 difler from the other legs, all being ambulator}- in character. 



Fig. 508.— J a n i - 



ROI'SIS CALIFOR- 

 NICA. Terminal 



PART OF BODY. 



« Crustacea of Norwaj', II, 1899, p. 98. 



