50 
PACIFIC SCIENCE, VoL VII, January, 1953 
leg shorter than first. Large chela 
compressed 15 
15(14). Scaphocerite reduced, not reaching 
to end of antennular peduncle; 
merus of third leg unarmed. 
Margins of large chela entire . . . 
C nanus (p. 90) 
Scaphocerite longer than the an- 
tennular peduncle; merus of 
third leg armed 16 
16(15). Depression on lower margin of 
large chela with both sides grad- 
ual; second carpal article of sec- 
ond leg broader than long 
C. hawaiiensis (p. 95) 
Depression on lower margin of 
large chela proximally delimited 
by a lobe; second carpal article 
of second leg longer than broad . . 
C. paragracilis (p. 96) 
17(13). Dactylus of third leg biunguicu- 
late 18 
Dactylus of third leg simple 19 
18(17). First carpal article of second leg 
about twice as long as second . . 
C. hawaiiensis (p. 95) 
Second carpal article of second leg 
about 3 times as long as first. 
Large chela subcylindrical, taper- 
ing; margins entire 
C. paralcyone (p. 99) 
19(17). Large chela without notches, 
grooves, or crests, usually quite 
cylindrical 20 
Large chela with either transverse 
groove, proximal to the dactylus, 
or pronounced lobes and depres- 
sions, especially along upper and 
lower margins; chela sometimes 
cylindrical 23 
20(19). Rostrum very small or absent; dor- 
sal Carina of carapace not extend- 
ing to tip of rostrum when pres- 
ent; orbital hoods with narrow 
to broad vertical keel anteriorly; 
chela subcylindrical 21 
Rostrum reaching about to middle 
of visible portion of first anten- 
nular article, with interorbital Ca- 
rina extending to tip; orbital 
hoods evenly rounded anterior- 
ly; chela compressed 22 
21(20). Second carpal article of second leg 
about 1. 5-2.0 times length of 
first; without tooth on basicer- 
ite; inferior internal margin of 
merus of large chela unarmed; 
no sexual dimorphism in small 
chela C brevipes (p. 103) 
Second carpal article of second leg 
about equal to first, not over 1.3 
times length of first; basicerite 
with tooth; tooth distally on in- 
ferior internal margin of liierus 
of large chela; dactylus of small 
chela of female broadened, twice 
as long as broad 
C clypeata (p. 107) 
22(20). First carpal article of second leg 
1.75-1.85 times length of sec- 
ond; merus of both large and 
small chelipeds with strong 
tooth C. paracrinita (p. 110) 
First carpal article of second leg 
about equal to length of second; 
tooth on inferior internal margin 
of merus of large chela reduced, 
none present on small chela . . . 
C. paracrinita y 2 . 1 . hengalensis (p. 110) 
23(19). Large chela with only transverse 
groove proximal to dactylus, 
without lobes on either margin; 
chela subcylindrical to com- 
pressed 24 
Large chela with transverse groove 
and also marked lobes on both 
superior and inferior margins and 
depressed areas on faces; chela 
always compressed 30 
24(23). Dactylus of third leg conical, large 
chela subcylindrical 25 
Dactylus of third leg triangular in 
section, inferior surface broad 
and flat, somewhat twisted, large 
