50 TRUE CRABS OF MONTEREY BAY 



Family PILUMNID^. 



Key to Genera of the Family Pilumnid^. 



a. General shape of carapace transversely oval, division between antero- 

 lateral and postero-lateral margins not sharp, latter curved; 

 front not markedly deflexed. Cycloxanthops 



aa. General shape of carapace not oval, antero-lateral and postero-lateral 

 margins meeting at an angle, latter nearly straight ; front much 

 deflexed. 

 b. Front divided by a closed fissure. Lophopanopeus 



bb. Front divided by an open rounded notch. Xanthias 



Genus CYCLOXANTHOPS Rathbun. 



Cycloxanthus A. Milne Edwards, Ann. Sci. Nat. (4), xx, 278, 1863. 

 Cycloxanthops Rathbun, Proc. Biol. Soc. Washington, xi, 164, 1897 (Type— C3;c/o.f- 

 anthops sexdecimdentatus (Edwards & Lucas)). 



Cycloxanthops novemdentatus ( Lockington ) . 

 Plate XII, fig. 36. 



Xanthodes? novem-dentatus Lockington, Proc. Calif. Acad. Sci., vii, 32, 1877. 

 Cycloxanthops novem-dentatus Holmes, Occas. Papers Calif. Acad. Sci., vii, 56, 1900. 

 Cycloxanthops novemdentatus Rathbun, H. A. E., x, 180, 1904. 



Represented in the collection by several specimens one of which was 

 obtained by W. F. Allen. The general color in life is a dull reddish 

 brown showing traces of purple at the posterior part of the carapace and 

 still more strongly on the ambulatory legs and below, thus somewhat 

 resembling Xanthias taylori; fingers of chelipeds black with teeth along 

 inner margins white. One young specimen shows the tendency to white 

 markings so common in the young of Lophopanopeus heathii. 



This species has not previously been reported north of San Pedro. 



Genus LOPHOPANOPEUS Rathbun. 



Lophopanopeus Rathbun, Bull. Lab. Nat. Hist. State Univ. Towa, 272, 1898 (Type— 

 Lophopanopeus bellus (Stimpson)). 



