50 University of California Publications in Zoology [Vol. 23 



Genus Spirontocaris Bate 



Carpus of second pair of legs consisting of seven segments, mandible with 

 incisor process, and palp of two segments. 



Key to the California Species of Spirontocaris 



I. One or more supraorbital spines present. 



A. Eostrum roughly subcircular ; three, more rarely two, supraorbital spines. 



(Not known south of Monterey.) 



prionota, p. 52. 



B. Eostrum not subcircular, more or less elongate; one or two supra- 



orbital spines. 



1. One supraorbital spine. 



a. Eostrum comparatively prominent, longer than eye; supraorbital 



spine relatively small, 

 i. Eostrum less than twice as long as the eye; armed above with 

 four spines, two of which are on the carapace, below with 

 three teeth on anterior third. (Known only from 448 -f- 

 fathoms.) 



washingtoniana, p. 55. 

 ii. Eostrum twice or more than twice as long as the eye; armea 

 above with ten teeth, last three of which are on the cara- 

 pace, below with six teeth, all of which are in front of 

 the middle of the rostrum. (Only one specimen known, 

 from Monterey.) 



affinis, p. 56. 



b. Eostrum inconspicuous, reduced to a spine on frontal margin, much 



shorter than the eye, supraorbital spines a very prominent 

 feature ; behind rostral spine anterior half of carapace is 

 carinated and bears three spines. (Known only from Laguna 

 Beach.) 



lagunae, p. 57. 



2. Two supraorbital spines. 



a. Abdominal segments laterally acute. Eostrum shorter than re- 



mainder of carapace. Dorsal spines continued posterior to 

 middle of carapace; spines on carapace proper four. (Not 

 known south of Point Arena.) 



lameUicornis, p. 53. 



b. First three abdominal segments laterally rounded. 



i. Eostrum longer than remainder of carapace. Dorsal spines 

 continued at least to or beyond middle of carapace ; spines 

 on carapace proper two or three. 



bispinosa, p. 54. 



ii. Eostrum shorter than, rarely as long as, remainder of carapace. 



a. Dorsal spines all in front of middle of carapace, spines on 



carapace proper two: (Known only from 211 -4- 

 f athoms. ) 



sica, p. 55. 



b. Dorsal spines continued posterior to middle of carapace; 



spines on carapace proper three or four. 



snyderi, p. 54. 



