158 PROCEEDINGS OF THE AMERICAN ACADEMY 



There has lately appeared an insufficient preliminary notice, 

 by Wladimir Schimkewitsch,* of an Astacas from the neighbor- 

 hood of the town of Toorkistan in the valley of the Jaxartes. It 

 is closely related to A. fluviatilis and A. leptodactylus, perhaps not 

 specifically distinct from one of these. Schimkewitsch affirms 

 that intermediate forms connect A. packypus with A. leptodactylus 

 (Government of Riazan) and A. leptodactylus with A. fluviatilis 

 (Governments of Toola and Moscow). 



68. ASTACUS PACHYPUS. 



Astacus packypus, Rathke, op. cit., p. 365. 1836. 



Astacus Caspius, Eichwald, Bull. Soc. Imper. Nat. Moscou, 

 1838, p. 149. — Fauna Caspio- Caucasia, p. 181, PI. XXXVI. 

 fig. 2. 1841. 



Astacus packypus, Erichson, op. cit., p. 91. 1846 (after 

 Rathke). 



Astacus Caspius, Erichson, op. cit., p. 92 (after Eichwald). 



Astacus fluviatilis, var. packypus et Caspius, Gerstfeldt, op. cit., 

 pp. 566, 584. 1859. 



Astacus packypus, Heller, op. cit., p. 217. 1863. 



Astacus packypus, Kessler, op. cit., p. 254. 1874. 



Hab. Brackish waters of the Caspian Sea and estuaries of 

 rivers flowing into the Caspian and Black Seas. 



69. Astacus Colchicus. 



Astacus Colchicus, Kessler, Bull. Soc. Imper. Nat. Moscou, 

 L. 2. 1876. 



Hab. Upper portion of Rion River and tributaries, Asiatic 

 Russia. It has been artificially introduced into some of the trib- 

 utaries of the Upper Koor (anc. Cyrus). (Kessler.) 



* Der turkestanische Flusskrebs. (Vorlaufige Mittheilung.) Von Wladimir 

 Schimkewitsch. . Zoologischer Anzeiger, VII. 339, 23 Juni, 1884. 



