628 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 113 
Hambly; 1 male.—East side, reef flat, 0-2 feet; September 14, 1958; 
Limbaugh and Chess; 1 ovigerous female. 
MeEaAsuREMENTS: Length of anterior part of carapace, from tip of 
rostrum to cervical groove: males, 1.3-4.2 mm.; females without 
eggs, 1.4-3.0 mm.; ovigerous females 2.0-4.7 mm. The length of the 
entire carapace in the midline is slightly less than twice as long 
as the anterior portion. 
Cotor: The following description is based on notes made in the 
field by E. S. Reese. Carapace anterior to cervical groove orange to 
red, except for gastric area which is dark gray or black; part posterior 
to cervical groove, pink to dark orange. Abdomen tan. Eye 
scales white. Eyestalks black with broad white band immediately 
proximad to cornea. Antennae, including scales, red. Chelipeds black 
with margins of hand red; fingers with yellowish to white cutting 
edges and orange to red tips. Walking legs red, dactyls orange. The 
darker colors change to orange in some preservatives, but the red 
color remains unchanged; preserved specimens of C. californiensis may 
therefore appear darker than those of C. explorator. The pattern 
persists for several years in most specimens. 
Remarks: No unfaded specimens of C. californiensis from the 
Mexican mainland have been available for comparison; the Clipperton 
specimens are therefore assigned to that species with reservations. 
Bouvier’s description of the color, presumably based on alcoholic 
specimens, agrees very well with that observed in the Clipperton series. 
Glassell’s mention of the unbanded dactyls of the walking legs and, 
even more significant, the reference by Steinbeck and Ricketts to the 
red coloration of the species in life indicate that C. californensis is 
distinct from C. obscurus Stimpson. 
Clipperton specimens of C. explorator and C. californiensis can be 
readily distinguished in life by the color of the walking legs: black 
in the former and red in the latter. Unfaded preserved material 
may be separated only slightly less easily by the banded ambulatory 
dactyls and narrow eyestalk band of C. explorator in contrast with 
the unbanded dactyls and broad eyestalk band of the latter. Faded 
specimens require careful examination and comparison, because the 
morphological characters are subject to considerable variation. 
In spite of the range of form exhibited by the major chela (figures 
4 and 6), that appendage probably affords the most useful means 
of distinguishing the two species when the color pattern has disap- 
peared. The fixed finger in C. explorator is characteristically short, 
broad, and poorly defined because the distal margin of the palm is 
oblique and almost continuous with the upper margin of the fixed 
finger. In C. californiensis, the distal margin of the palm is more 
nearly transverse, and the angle it makes with the fixed finger is 
