A.STACUS. 14:i 



Antaeus pallipes, Li ai boi a i r, Mdtn Soc Soi. Nat. Strasbourg, V. 7 (separate pagination), PI. II., 111. 



figs. ;>-:> a, L85 3 

 Astacus pallipes, tax. ft • ■■-. Li bj boi i i et, Mem. Sop. Sci. Nat. Strasbourg, \ r . 9, 1 ^ r, s . 

 Astacus torrentium (Steiukrebs) (in part), Gerstfeldt, Mem. Lead. [mper. Sci. St. P^tersbourg, IX. 577, 



L859. 

 Antaeus saxatilis, Grube, Eiu Ausflug nach Triest und dera Quarnero, p. 73, L8G1. 



Astacus saxalilis, Eeller, Die Crust! en dessiidlicheu Europa, |>. 217, Taf. VII. ligs. 3, 5, 1863. 



Astacus fontinalis (l'6crevisse a pieds blanes), Carbonnier, L'Ecrevisse, p. 8, 1869. 



Potamobius astacus, (I. B. Sowerby, Continuation of Leach's Malacostraca Podophlbalma Britanu 



XVIII, MX., Tab. \X\1V. fig. 1, 1875. 

 Astacus fluviatilis, IIlxxey,* The Crayfish, passim, and p. 230 in particular, Frontispiece and figs. 1-60, 



1S80. 

 Astacus torrentium, Hi \u:i. : op. cit., p. 296, tig. 61, a, d, g, fig. 62, a, d, 1880. 

 Astacus pallipes (der Dolilenkrebs), Ki.uxzixger, Jahresh. Vereins vaterland. Naturkunde Wiirttemberg, 



XXXVIII. Jahrg., p. 341, 1882. 

 Astacus pallipes, Faxon, Proc. Amcr. Acad. Arts and Sci., XX. 154, 1881. 



Under the name "Steinkrebs" the older authors appear to have con- 

 founded A. torrentium and A. pallipes. They were first separated as distinct 

 species in 1858 by Lereboullet with the names A. longicornis and A. pallipes. 

 Gerstfeldt (1859) seems to have had very little material from without the 

 bounds of the Russian Empire. Of the "Steinkrebs" he had seen only five 

 ill-preserved dried examples from the Rhone, which, as appears from his 

 description of them (p. 577), belong to A. pallipes. He considers them to be 

 the same species as that described by Schrank and Koch, i. e. A. torrentium. 

 Compared with A. torrentium, A. pallipes has a narrower rostrum with a 

 longer and narrower acumen; the median keel is more evident, especially 

 near the tip of the rostrum ; the antennae are shorter, and the peduncle of 

 the antennae overreaches the tip of the rostrum by only a small fraction 

 of the length of the terminal segment, while in A. torrentium it surpasses the 

 rostrum by the whole length of the terminal segment; the longitudinal ridge 

 on the lower face of the antennal scale is not toothed, as in A. torrentium ; 

 behind the cervical suture are several lateral spines ; the chela 1 are more 

 coarsely and sparsely tuberculate. For a detailed comparison of these two 

 species, see Klunzinger. op. cit. 



A. pallipes and A. torrentium have a rudimentary pleurobranchia on each 

 side of the penultimate and antepenultimate somites. In all the other 

 species of Astacus which I have examined there is a third pair on the preced- 

 ing somite. The first abdominal appendages of the male A. paVipes arc 

 figured by Brocchi, Ann. Sci. Nat., (V Se'r., Zool. et Paleontol., Tom. II.. PI. 

 XIII. figs. 12, 13 ("Astacus fluviatilis " from Vaucluse). They agree in form 



* Ilnvh'N leaves the question of the specific or the varietal value of the forms ./. nobilis and A torren- 

 tium (= A.Jlitriiililit and ./ [mlli/ies) undecided. 



