38 University of California Publications in Zoology (Vou. 23 
KeryY TO THE CALIFORNIA GENERA OF THE PONTONIIDAE 
I. Rostrum short, less than one-half length of carapace, depressed, bent down- 
ward, not dentate. One of the second pair of legs with very large chela. 
(Known only from off Santa Cruz Island.) 
Pontonia, p. 38. 
II. Rostrum often about as long as carapace, compressed, usually dentate, not bent 
downward. Second pair of legs long, slender, and equal. (Not known 
north of Santa Catalina Island.) 
Periclimenes, p. 39. 
Genus Pontonia Latreille 
Rostrum short, depressed, bent downward; not dentate; with or without a 
keel below at the free end. Both flagella of antennules short; thicker of the two 
bifid. Antennal scale of moderate length only, broad. One of the second pair of 
legs with very large chela. 
Pontonia californiensis Rathbun 
Pontonia californiensis Rathbun, Proc. U. S. Nat. Mus., 24, 902, 1902; 
H. A. E., 10, 33, fig. 11, 1904; Borradaile, Trans. Linn. Soe. London 
(CAO 5 (Ny alty arsty atl, eer 
Fig. 23. 
Pontonia californiensis, 9; dorsal view, X 437 (from Rathbun, U. 8. 
N. M.). 
