1921] Schnitt: The Marine Decapod Crustacea of California 81 
Genus Processa Leach 
One of the first pair of legs chelate and the other simple; rarely both chelate. 
Second pair of legs unequal, carpus multiarticulate. Rostrum short. 
Processa canaliculata Leach 
Plate 12, figure 6 
Processa canaliculata Leach, Mal. Podoph. Brit., pl. 41 and corresponding 
text, July 1, 1815; Rathbun, Bull. U. 8. Fish Comm., 20, pt. 2, 104, 
1900 (1901); H. A. E., 10, 110, 1904. 
Characters.—Rostrum slender, about half as long as eye-stalks, unarmed 
except at apex, which is obscurely bifid and furnished with a few long hairs. First 
pair of feet rather stout, reaching a little beyond the antennal scale; right, or 
chelate foot with palm a little longer than carpus or fingers; left or simple foot 
of first pair with dactylus about one-fourth the length of propodus; remaining 
feet slender; second pair unequal. 
Dimensions.—See Remarks. 
Type Locality.—Toreross, southern coast of Devon, England. 
Distribution.—Europe; Madeira; Bermudas; from North Carolina to Trini- 
dad, including Gulf of Mexico and West Indies; from San Diego, California, to 
Panama Bay; Japan; Amboina. Shallow water to 111 fathoms (Rathbun). 
Remarks.—F rom Miss Rathbun (1904a, p. 110), I take the following: 
Two specimens of unusual interest were taken at San Diego, California, by 
D. S. Jordan, in 1880. They are about 22 mm. long, and differ from typical 
specimens in having the left foot of the first pair similar to the right, or chelate. 
One specimen is a female and has both chelipeds present. The other is so muti- 
lated that the sex is indeterminable; it has a left cheliped, the right is missing. 
This form might perhaps be deemed a distinct species or genus were it not that 
among a lot of specimens from Cedar Keys, Florida, both forms occur. From 
this locality they are small (12 to 15 mm. long), and five specimens are bichelate 
while four have only a right cheliped, the left foot being simple, as in typical 
P. canaliculata. These two forms from the same locality present no other 
appreciable difference. 
Aside from this remarkable dimorphism in the left first foot the species is a 
most variable one. The rostrum may be half as long as the eye. The eyes while 
always of good size are not uniform, in some cases larger and more reniform, 
with the cornea extending on the outer side almost back to the carapace. The 
second joint of the antennulae varies from one and one-fourth to twice the length 
of the third joint. The antennal scale may be a little more than half as long as 
the carapace (rostrum excluded) or even two-thirds as long as the carapace; it 
may be just as long as the antennular peduncle or distinctly longer. Of the speci- 
mens examined, those from the west coast of Mexico and Panama Bay have the 
largest eyes; they agree fairly well with the description and figure of Bate’s 
P. processa from Amboina, 15 fathoms. 
Family CRAGONIDAE (CRANGONIDAE) 
(CRANGONIDAE OF AUTHORS, NOT CRANGONIDAE PAGE 73.) 
Rostrum generally small, usually dorsally flattened, and not toothed, or want- 
ing; in Paracrangon only it is a suberect, elongated, laterally compressed spine. 
Eyes generally free, in Nectocrangon only are they covered by the carapace. 
Mandibles without incisor and palp. First pair of legs subchelate and stouter 
than the second. Second pair slender and equal, with unsegmented carpus, either 
minutely chelate or simple. 
