50 University of Califormia Publications in Zoology [Vow 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. Rostrum roughly subcircular; three, more rarely two, supraorbital spines. 
(Not known south of Monterey.) 
prionota, p. 52. 
B. Rostrum not subcircular, more or less elongate; one or two supra- 
orbital spines. 
1. One supraorbital spine. 
a. Rostrum comparatively prominent, longer than eye; supraorbital 
spine relatively small. 
’ i, Rostrum 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 +- 
fathoms. ) 
washingtoniana, p. 5d. 
ii. Rostrum twice or more than twice as long as the eye; armed 
above with ten teeth, last three of which are on the ecara- 
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. Rostrum 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. Rostrum 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.) 
lamellicornis, p. 53. 
b. First three abdominal segments laterally rounded. 
i. Rostrum 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. Rostrum 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 + 
fathoms. ) 
sica, p. 55. 
b. Dorsal spines continued posterior to middle of carapace; 
spines on carapace proper three or four. 
snyderi, p. o4. 
