74 University of California Publications in Zoology (Vou. 28 
Genus Crangon Weber 
Rostrum short and usually spiniform. Antennules with basal article and spine 
reduced. Distal joint of third maxillipeds drawn out to a point and almost 
unarmed. No pterygostomian spine on carapace. Thoracic legs with epipods; 
dactyli simple. 
Kry TO THE CALIFORNIA SPECIES OF CRANGON 
I. Front trispinose; rostrum present, orbital hoods armed with spines. 
A. Basal joint of antennae with a spine. 
1. Merus joints of third and fourth pair of legs with a spine below at 
inferodistal angle. A sulcus between eye-shields and rostrum. 
Large hand seulptured, dactyl closing horizontally. Smaller hand 
with a superior spine above articulation of dactyl only, no external 
spine. (Not known north of Farallon Islands.) 
dentipes, p. 74. 
No spines on merus joints of third and fourth pairs of legs; no 
suleus between eye-shields and rostrum. 
a. Dactyl of larger hand closing horizontally, laminate. Large hand 
sculptured; smaller hand spined. (Not known north of Mon- 
terey. ) 
to 
bellimanus, p. 75. 
b. Dactyl of larger hand closing vertically. Large hand smooth; 
smaller hand without spines. (From Monterey to Santa 
Barbara. ) ; 
equidactylus, p. 76. 
B. Basal joint of antennae without a spine. Smaller hand with a superior 
spine above articulation of dactyl, no external spine. As no speci- 
men, only the original description, has been seen it is not known how 
the dactyl of the larger hand opens. (Known only from Santa 
Barbara. ) 
barbara, p. 76. 
II. Front unispinose; rostrum present, but no spines on orbital hoods. A deep 
suleus between eye-shields and rostrum. Smaller hand smooth without 
spines; dactyl of larger hand opening vertically. (Not known north of 
San Pedro.) 
californiensis, p. 76. 
Crangon dentipes (Guérin) 
Alpheus dentipes Guérin, Exp. Sci. Morée, Zool., p. 39, pl. 27, fig. 3, 1832. 
Alpheus clamator Holmes, Oceas. Papers Calif. Acad. Sci., 7, 182, pl. 2 
figs. 39, 40, 1900; Baker, Rep. Laguna Mar. Lab., 1, 106, 1912. 
Alpheus dentipes Rathbun, H. A. E., 10, 108, 1904; Hilton, Jour. Ent. Zool., 
Pomona Coll., 8, 67, fig. 6, 1916. 
a 
Fig. 50. Crangon dentipes; a, small hand; b, large hand (after Holmes). 
