ISOPODS OF NORTH AMKRICA. 483 



The color of the species is u lig-iit brown, somewhat mottled. 



Prof. S. J. Holmes describes the type specimen" of this species, 

 which 1 hav(> not b(MMi fortunate enough to obtain for examination. 

 The description uiven above is from specimens collected at Lake 

 Washing-ton, Seattle, and which I still do not think differ from the 

 type as described by Professor Ilolmes in any essential characters. 

 The type specimen is imperfect, one uropod being gone and the other 

 with the inner branch partly regenerated. The specimens which 

 Professor Holmes collected at Point Arena have ""caudal stylets 

 shorter than the abdomen,'' as is also true of my specimens, and 

 he considers the Point Arena specimens as young specimens of this 

 species. 



A slight ditierence in the length of the antenna* often occurs among 

 the individuals of a species where the fiagellum is nudti-articulate. 

 If may be due to a difference in sex or a ditiei-encc; in age. 



The onl}' important difference is in the fact that the three last seg- 

 ments of the thorax are entire in the type, as descri})ed by Professor 

 Holmes, whereas they are posteriorly notched in the specimens fi'om 

 Lake Washington. The margins of the segments often appear entii-e 

 when the emargination is filled by the epimeron, so that withouf 

 having seen the type I would be unwilling to give a new name to the 

 specimens from Lake Washington, which are otherwise in so close 

 agreement with Professor Holmes's description. 



69. Genus C^CIDOTEA Packard. 



Bod}^ narrow, elongate. Eyes wanting. Head large, not nari'ower 

 than the first thoracic segment and longer. Terminal segment of body 

 nnich longer than broad. 



ANALYTICAL KKY TO THE SI'ECIES OF THE (iENl'S CKCinOTEA. 



a. Propoclus ot first pair of legs armed with one or more triangular processe.'^. 



h. ProjKxluH of first pair of legs armed with two long triangular processes and tlnce 

 short ones. Uropoda about as long as the terminal segmentof the body; the 

 inner branch of the uropoda is two-thirds as long as the peduncle; the outer 



branch is two-thirds as long as the inner branch dvcklotea sti/gia Packard 



I/. Propodus of first pair of legs armed with a triangular process near the distal 

 end and with a long spine at the proximal extremity. Uropoda shorter than 

 terminal abdominal segment, about one-half its length; the peduncle is as 

 long as the inner branch; the outer branch is one-fourth shorter than tlie inner 



branch ( 'ncidotea nickajackenKis Packard 



a''. Propodus of first pair of legs not armed with triangular processes, but edged 

 inside with spines. 

 h. First pair of antennje, with flagelluin composed of eleven articles, extend one- 

 third ttie length of the fifth article of the peduncle of the second antenn;e. 



«Proc. Cal. Acad. Sci. (3), III, 1904, pp. 321-323. 



28589— U5 28 



