38 



University of California Publications in Zoology [Vol. 23 



Key to the California Genera of the Pontoniidae 



• I. Eostrum 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. Eostrum 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 



Eostrum 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 Eathbun, Proc. TJ. S. Nat. Mus., 24, 902, 1902; 

 H. A. E., 10, 33, fig. 11, 1904; Borradaile, Trans. Linn. Soc. London 

 (Zool.), (2), 17, 389, 391, 1917. 



Fig. 23. Pontonia californiensis, J; dorsal view, X 4^ 7 (from Eathbun, U. S. 

 N. M.). 



