138 A KEVISION OF THE ASTACID.E. 



vision by Erichson.* Of the described European species, A. angulosm Rathke, 

 A. pachypus Rathke, and A. Caspius Eichwald, were known to Erichson only 

 through the previous descriptions. He suggests that A. Caspius may prove 

 to be the same as A. pachypus, a surmise that was afterwards shown by Gerst- 

 feldt to be just. Erichson had the opportunity to examine Koch's types 

 of A. torreidium, saxutilis, and trisiis, and notes their clear specific separation 

 from A. fluviatilis, and their close affinity with each other. He shows that 

 the dark color of A. tristis is due to a coating of adhesive mould, and dis- 

 misses the question of the specific value of the differences with the remark 

 that the distinctions may have been more evident in living specimens. 



In 1859 the European Astaci were subjected to a second revision at the 

 hands of Gerstfeldt.f The material at Gerstfeldt's command was rich in speci- 

 mens from Russia, but poor in examples from Central and Western Europe. 

 Gerstfeldt reaches the conclusion, that all the described European species of 

 Astacus may be reduced to two valid species, A. fnviatilis and A. torrentiuni 

 (Steinkrebs). He justly points out the identity of A. pachypus Rathke and 

 A. Caspius Eichwald, and further claims that A. leptodaetylus Eschscholtz, 

 A. angulosus Rathke, and A. pachypvs Rathke, are but varieties of A. fuii/i- 

 tilis, resulting from conditions of climate and of the water inhabited by 

 the several forms. Of the so-called Steinkrebse of the central and western 

 parts of Europe, Gerstfeldt appears to have had but five specimens, all from 

 the Rhone. These he regards the same with Cancer torrentium Schrank, 

 A. saxatilis Koch, A. iristis Koch, and A. longicarnis Lereboullet. In reality 

 Gerstfeldt's Steinkrebse belonged to the species described and figured the 

 previous year (in a memoir unknown to Gerstfeldt) by Lereboullet,t under 

 the name A. pallipcs (Dohlenkrebs), a distinct form from Cancer torrcntinni 

 Schrank (= A. saxatilis, tristis, and torrcniinm of Koch, A. longicornis of Lere- 

 boullet). 



In 1869 Heller described five species from Southern Europe; viz. A. flu- 

 vial His Rondelet, A. lepioilactylus Eschscholtz, A. angulosus Rathke, A. pachypus 

 Rathke, and "A. saxatilis Koch." As synonymes of A. saxatilis, Heller in- 

 cludes A. sa.mfilis Koch, A. trisiis Koch, A. toirculimii Schrank et Koch, and 

 A. fluriatids Bell. Heller's A. saxatilis is the species described by Lereboullet 



* Ucbersicht der Arten der Guttling Astacus. Arch. Naturgescli., XII. Jahrg., pp. 8(1-103, ISifi. 



f Ucbcr die Flusskrebsc Enropa's. Mem. Acrid. Impur. Sci. St. Petersbourg, IX. 5-19-589, 1859. 



| Description de deux nouvelles Especcs d'^crevisses do uos Rivieres. Mem. Soc. Sci. Nat. Stras- 

 bourg, Tom. V., 1858, 11 pp. 3 pi. 



Die Crustaceeu des siidlicben Europa. Crustacea Podoplithalmia, pp. 212-218, Taf. VII. figs. 3-6, 

 1803. 



