1921] Schnuitt: The Marine Decapod Crustacea of California 35 
Kerry TO THE CALIFORNIA GENERA OF THE PALAEMONIDAE 
I. Rostrum prominently toothed above only, about two-thirds as long as carapace, 
pronouncedly convex above, armed with five to seven teeth, with one or two 
small teeth below near tip; behind rostrum there is a median gastric spine. 
An hepatic spine present. Mandible without palp. (Not known north of 
San Diego Bay.) 
Urocaris, p. 37. 
II. Rostrum prominently toothed above and below. No hepatic spine. 
A. Rostrum about as long as carapace, armed with six to ten teeth above, 
one or two of which are behind the orbit, and with two to four teeth 
below. Mandible without palp. (Known only from San Pedro.) 
Palaemonetes, p. 36. 
B. Rostrum longer than carapace; armed with seven to eight teeth above, 
one or two of which are behind the orbit, and with three teeth below. 
Mandible with palp. (Not known north of San Diego.) 
; Palaemon, p. 35. 
Genus Palaemon Fabricius 
Rostrum prominently toothed above and below. Carapace furnished with 
antennal and branchiostegal spines, but without hepatic spine. Mandible with 
three-jointed palp. 
Palaemon ritteri Holmes 
Palaemon ritteri Holmes, Proce. Calif. Acad. Sei. (2), 4, 579, pl. 21, figs. 
29-35, 1895; Oceas. Papers Calif. Acad. Sci., 7, 216, 1900; Rathbun, 
HAS ti, 10,029, 1904. 
a b 
Fig. 21. Palaemon ritteri; a, lateral view of carapace; b, mandible (after 
Holmes). 
