CLIPPERTON ISLAND DECAPODS—-CHACE 
- ay 
é é- ts 
f- 2.8mm. 
d 
9-2.1mm. 
O 
ro) 
ovig. 2- 3.0mm. 
o- 3.9mm. 
4 
igi ee 
es és 
J i 
o- 4.7mm. ovig.2- 4.6mm. 
Ficure 6.—? Calcinus californiensis Bouvier, left chelae, X 6.0, of specimens having anterior 
carapace lengths as indicated. 
always apparent even though broadly obtuse. In those specimens 
of each species in which that angle is nearly identical (e.g., figures 
4g and 6j), it will be noticed that the chela of C. explorator is of the 
elongate form and that of C. californiensis is short and broad with 
convex margins. If, therefore, specimens of each species having 
similarly shaped chelae are compared, there is little difficulty in 
separating them. 
Another character that is often useful in distinguishing C. californi- 
ensis is provided by the propodus of the left second walking leg 
(third pereiopod). In C. explorator, the outer surface of that segment 
is rather evenly convex and forms a blunt angle with the comparatively 
broad upper surface. In most specimens of C. californiensis, the 
upper part of the outer surface is flattened, or even concave, and 
rugose, and the upper surface is narrower than in C. exploraton; the 
rugose sulcus on the outer surface approaches, but never equals, the 
condition found in C. tibicen (Herbst) of the western Atlantic. 
There is also a tendency for the eye scales of C. californiensis to 
bear more teeth than those of C. explorator, but that character is of 
