214 CALIFORNIA ACADEMY OF SCIENCES. 



margin. Maxillipeds not reaching the tip of the rostrum, the exognath not 

 reaching the tip of the penultimate joint. Anterior chelipeds short; car- 

 pus short and excavated to receive the propodus. Second pair of chelipeds 

 much longer than the first, carpus much longer than the hand and not 

 distally excavated. The succeeding pereopods are longer than the cheli- 

 peds; merus and carpus with a few spines on the outer side; dactyls of 

 the first two pairs about one-fourth the length of the propodi and armed 

 below with numerous spines; dactyls of the last pair longer than those of 

 the preceding pairs and of a different shape, the lower margin finely pec- 

 tinated nearly to the terminal claw behind which are two spines. Telson 

 rounded above and tapering to a broadly rounded or truncated extremity; 

 upper surface armed with two pairs of short spines. Uropods longer than 

 the telson. 

 Length 1.5 in. 



Described from four specimens collected in a small 

 stream near San Gabriel, Los Angeles County, Calif., 

 by Mr. N. C. Trew.* All the exopods in some of the 

 specimens were broken off, but in others they were 

 present on the first two pairs of pereopods. I have found 

 no trace of exopods on any of the posterior pairs; they 

 may have been present and become broken off but I do 

 not think this is probable. Collection University of 

 California. 



Genus Caridina Milne-Edwards. 



Carapace with a well developed rostrum. Pereopods devoid of exopods. 

 Carpus of the first exopods distally excavated; that of the second pair not 

 excavated. 



Type. C. typus MILNB-EDWARDS. 



Caridina pasadenae Kingsley. 



Caridina pasadence KixGSLEY, Bull. Essex Inst., Vol. XXVII, 1897, p. 98, 

 PI. Ill, figs. 1-7. 



Carapace not carinated anteriorly and furnished with a suborbital and 

 an antenual spine. Rostrum three-fourths the length of the carapace, 

 smooth above, bifid at the apex, and occasionally armed with a single 

 tooth on the lower margin. Basal scale of the antennules reaching 

 slightly beyond the tip of the first joint; inner margin of the first joint 



