ASTACTS. 141 



A. One tubercle on each side of lln- base of rostrum. 



a. Tip of roslniiu nui exceeding || lr distal eud of the penultimate segmenl of anlennidc. 



Kostriim not eimnale at the lip. No spines mi the sides .if the carapace behind the 



cervical groove l.tomHlitm. 



l>. Tip of roslrum almost attaining lliedislal end of tin- terminal Segment of tile aiilcmiiilc. 

 A keel or median crest near (lie tip oft lie rnslnim. One or more spines on tin 



sides of the carapace behiud the cervical groove /.//////>* 



B. Two tnliereles, one behind the other, on each side of the base of the rOHl rum. 



11. Margin of rostrum not uYnlicnlalc. 



a. Margin of rostrum granulated, not continued hack of the anterior post oiliilal 



tubercle. Posterior post-orbital tubercle slightly developed I. /lnn,i/ilix. 



/3. Margin of rostrum smooth, continued back on the, carapace as a distinct ridge as 

 far as the posterior post-orhila.1 tubercle. Posterior post.orliilal tubercle well 

 developed, provided with a spine A. Ciilcliii-itx. 



b. Margin of rostrum denticulate. 



a. Click Hat. Kustrnni longer than peduncle of aiit.ennnle. l!asal angle of c\lerii;il 



border of antenna! scale spiuous /.//,/,/,/,/,/<//. 



/3. Chela thick. Kostrum equal in length to peduncle of aiitennnle. l',as;d angle 



of external border of aulcimal scale not spiuous A. paclii/put. 



6. Astacus torrentium. 



Cancer torreafiiiiii (Slcinkrebs), SCHRANK, Fauna Boica, III. 21-7, 1803. 



Astaciis torrt'iiliitiii I Sk-iukrebs), WOLF, Mag. neuesten Zustand Naturknnde, heraiisgegeb. v. Johaini Ilein- 



ricli Voigt, XI. 42-15, Taf. I. figs. 1, 2, 1806. 

 Astaeus saxntilis, Kocu, Deutschlands Crustaceeu, Myriapodeu und Aracliniden, I left 7, No. 1, with fig. 



(Panzer and llerrich-Schhffer's Deutschlands Insceten, Heft 140, No. 1), 1S35? 

 Astacns Mali*, Konr, op. cit., Heft 7 (Un), No. 2, with fig., 1835 ? 

 Astacus torrentium, KOCH, op. cit., Heft 3(3 (186), No. 24, with tig., 1841. 

 Astaciis torrentium, ERICHSON, Arch. Natnrgcscli., XII. Jahrg., I. ( J2, 1846. 

 Astacus saxatilis, ERICHSON, op. cit., p. W, IS Hi. 

 Axtactts fristis, ERICHSON, op. ci/., p. 93, 1810. 



Steinkrebs, LEREBOULLET, Coinpt.es Ucudus Acad. !?ei. Paris, XXXIII. 37!), 1851. 

 Aslacun loiirjieoruis, LEKEBOULLET, Mem. Soc. Sci. Nat. Strasbourg, V. 2 (separate pagination), PI. I. HL'S. 



2-2 , 1858. 

 Astacns torrentium (Steinkrebs) (in part), GERSTFELDT, Mem. Acad. Impcr. Sci. St. Petcrsbourg, IX. 574, 



579, 581, 584, 1859. (After Koch, Erichson, and Lereboullet.) 

 Astacus torrentium (Steinkrebs), KLUNZINGER, Jahresh. Vereins vatcrlandl. Naturkuiidc Wurttemberg, 



XXXVIII. Jahrg., p. 340, 1882. 

 Asturus toi-rentiiim, FAXON, Proc. Auicr. Acad. Arts and Sci., XX. 153, 1SS1-. 



Koch's A. w.>v////.v. J. //v'-v//s, and A. torrentium are without doubt one and 

 the same species, equivalent to A. tomnthun (Schrank) Wolf. According to 

 Koch, A. saxatilis is distinguished by a slightly carinated rostrum, whereas 

 in A. tristis and A. toirentium the rostrum is not carinated ; but Erichson, who 

 examined Koch's types, tells us that there is an indication of a median ros- 

 tral carina in A. tristis and .1. tonmiiinii also. The carina is certainly shown 

 in an exaggerated form in all of Koch's figures. The dark color of .1. //vV/.v 

 came from a coating of mould, according to Erichson, and the broad abdo- 

 men is simply a sexual character. 



