1921] Schmitt: The Marine Decapod Crustacea of California 51 



II. No supraorbital spine or spines. 



A. Rostrum as long as or longer than rest of carapace. 



1. Terminal half (at least) of rostrum devoid of spines above. Sixth 



abdominal segment not longer than the telson. 



a. Sixth abdominal segment less than twice as long as 'wide. Ros- 



trum deep, one-fourth as deep as long. (Not known north of 

 Monterey Bay.) 



carinata, p. 62. 



b. Sixth abdominal segment more than twice as long as wide. Ros- 



trum more slender, 

 i. Scale at base of antennules extending beyond first segment. 

 Third maxilliped with epipod. (Not known south of 

 Drake's Bay.) 



flexa, p. 58. 

 ii. Scale at base of antennules not reaching beyond or only 

 slightly beyond first segment. Third maxilliped without 

 epipod. (Not known south of Santa Catalina Island.) 



gracilis, p. 59. 



2. Terminal half of rostrum with spines (in part, at least). 



a. Sixth abdominal segment longer than telson. 



decora, p. 61. 



b. Sixth abdominal segment shorter than telson. 



i. Third maxillipeds exceeding antennal scale. Rostrum with 

 six to eight spines above. 



paludicola, p. 64. 

 ii. Third maxillipeds not exceeding antennal scale. 



a. Rostrum with more than eight spines above. (Within 



California region known only from Monterey Bay.) 



layi, p. 63. 



b. Rostrum with five or six spines above. 



i. Third maxillipeds reaching about to the middle of the 

 antennal scale. (Not known north of San Francisco 

 Bay or south of Laguna Beach.) 



franciscana, p. 60. 

 ii. Third maxillipeds reaching nearly to end of antennal 

 scale. (Not known south of Santa Cruz.) 



Mncaidi, p. 63. 



B. Rostrum shorter than rest of carapace. 



1. Rostrum elongate, reaching beyond middle of antennal scale. 



a. Upper and lower limbs of rostrum deep and with convex margins. 



(Known only from 178 -j- fathoms.) 



macrophthalma, p. 72. 



b. Upper and lower margins of rostrum not both convex. 



i. Upper margin of rostrum concave; rostrum armed above with 

 six teeth, the last one of which is on the carapace ; below 

 with three teeth. (Known only from 266 4- fathoms.) 



bracltydactyla, p. 72. 

 ii. Upper margin of rostrum straight; rostrum armed above with 

 six to seven teeth, the last two of which are pn the cara- 

 pace; below with two to four teeth. (Not known north 

 of Monterey Bay. ) 



picta, p. 68. 



