38 TRUE CRABS OF MONTEREY BAY 



d. Carpus of cheliped with a single spine above at distal 

 end ; dactyls of ambulatory legs, especially those of 

 last pair, much flattened. C. magister 



dd. Carpus of cheliped with 2 spines, one above at distal 

 end and a second below this on inner angle; dac- 

 tyls of ambulatory legs slender, not flattened. 



C. gracilis 

 cc. Antero-lateral teeth not low (projecting more than 1-3 the 

 length of base), often spiny pointed; fingers of cheliped 

 dark-tipped; merus of outer maxilliped not elongated, 

 truncated anteriorly. ' 

 d. Carpus of cheliped with 2 spines, one above at distal end 

 and a second below this on inner angle; hand 

 roughened and armed above with 2 or more spines 

 (sometimes inconspicuous). 

 e. Antero-lateral teeth acute, strongly produced, alter- 

 nately large and small; carapace pubescent. 

 /. Tenth antero-lateral tooth conspicuous, nth 

 present; dactyl of cheliped spiny. 



C. gibbosulus 



ff. Tenth antero-lateral tooth inconspicuous, nth 



not present; dactyl of cheliped not spiny. 



C. jordani 

 ee. Antero-lateral teeth broadly triangular, not strong- 

 ly produced, subequal; carapace not pubescent. 



C. amphioetus 



dd. Carpus of cheliped with a single spine above at distal 



end ; hand smooth or granulated, without spines. 



e. Carapace widest at 8th antero-lateral tooth, nth 



distinct; dark color on dactyls of cheliped 



reaching more than ^ the length of outer 



margins ; under parts spotted or blotched 



with reddish. C. antennarius 



ee. Carapace widest at 9th antero-lateral tooth, loth 



inconspicuous ; dark color on dactyls of cheli- 



peds reaching less than }i the length of outer 



margins ; under parts of uniform light color. 



C. anthonyi 

 aa. Antero-lateral and postero-lateral margins not meeting at a distinct 

 angle; carapace widest at 7th or 8th tooth; 12 or 13 teeth. 



C. oregonensis 



