74 University of California Publications in Zoology [ V <> L - 23 



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. 



Key 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 sculptured, dactyl closing horizontally. Smaller hand 

 with a superior spine above articulation of dactj r l only, no external 

 spine. (Not known north of Farallon Islands.) 



dentipes, p. 74. 



2. No spines on merus joints of third and fourth pairs of legs; no 



sulcus 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.) 



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 



sulcus between eye-shields and rostrum. Smaller hand smooth without 



spines; dactyl of larger hand opening vertically. (Not known north of 



San Pedro.) 



calif omiensis, p. 76. 



Crangon dentipes (Guerin) 



Alpheus dentipes Guerin, Exp. Sci. Moree, Zool., p. 39, pi. 27, fig. 3, 1832. 

 Alpheus clamator Holmes, Occas. Papers Calif. Acad. Sci., 7, 182, pi. 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 b 



Fig. 50. Crangon dentipes; a, small hand; b, large hand (after Holmes). 



