OF ARTS AND SCIENCES. 149 



54. Cambarus Montezuma. 



Gambarus Montezutnce, Saussure, Rev. Mag. de. Zool., 2 e Ser. 

 IX. 102. 1857. — Mem. Soc. Phys. Hist. Nat. Geneve, XL V. 

 459, PI. III. fig. 22. 1858. 



Gambarus Montezutnce, var. tridens, Von Martens, op. eit., p. 

 130. 1872. 



Hab. Mexico. 



G. Montezumce and G Shufeldtii are small species, distinguished 

 from all others by the presence of hooks on the third segment of 

 the second and third pairs of legs in the male. Dr. Hagen has 

 given me the following note on Saussure's types of G. Montezumce 

 in Berlin : " The types are in alcohol, male, form I., and female. 

 In the male (young) the rostrum is nearly rounded in front. 

 Another jar contains male, form II., and female, also from Saus- 

 sure, with tridentate rostrum. The second and third pairs of legs 

 are hooked, as is stated by Saussure." The majority of the 

 specimens which I have seen, amounting to about seventy, have 

 the lateral spines on the rostrum (Von Martens's var. tridens) ; 

 but in some these spines are very small, and in others-reduced to 

 a mere angle at the base of the acumen. Six specimens in the 

 Museum of Comparative Zoology from near Parras, Cohahuila, 

 have the section of the carapace behind the cervical groove shorter, 

 the areola much broader. These may prove to be a distinct species. 

 Five dry specimens in the same collection come from Mazatlan. 

 It appears from these that the genus Gambarus extends in Mexico 

 to the Pacific Ocean. Other localities are the neighborhood of 

 the city of Mexico ; * Puebla ; Lake San Roque, Trapuato. 



55. Cambarus Shufeldtii. 



Gambarus Shufeldtii, Faxon, supra, p. 134. 

 Hab. Neighborhood of New Orleans, Louisiana. 



56. Astacus (Cambaroides) Japonicus. 



Astacus Japonicus, De Haan, Crustacea of Siebold's Fauna 

 Japonica, p. 164, PI. XXXV. fig. 9. 1842. 



Astacus Japonicus, Erichson, op. cit., p. 94. 1846. 



Astacus Japonicus? Kessler, Bull. Soc. Imper. Nat. Moscou, 

 XL VIII. 364. 1874. 



Hab. Japan. 



The three species A. Japonicus, A. Dauricus, and A. Schrenchii, 

 from Japan and the basin of the Amoor River, widely separated 



* I have seen specimens from Lake Tezcoco, which is said to be salt. 



