6 A REVISION OF THE ASTACID.^. 



abdominal appendage ol' the male Cariibarus robustus (PI. XIII. fig. 15), and criticises 

 Hagen for retaining the genus Carabarus as distinct from Astacus, and for dividing the 

 genus into upwards of thii'ty species, based chiefly on tlie form of the male appendages. 

 With regard to the first point, the generic value of Cambarus, Brocchi asserts that, of 

 all the characters urged by Hagen as a warrant for the establishment of tlie genus, only 

 one seems to him to be of an}' importance, namely, the absence of the posterior branchiae, 

 and this he has not hem aUc to verifij ! He goes on to say (p. 26) : " Si Ton prend, par 

 exemple, le caractere tire de la ])r^sence d'un ongle a la troisieme et quatriunie paire de 

 pattes, je feral observer qu'une seule esptee Cambarus, le Cambarus acutits, pr^seute cet 

 appendice ;\ la troisieme et quatrieme paire de pattes ; tons les autres ont seulement 

 les quatrieme et cinquieme paires unguicnih'es, caractere qui leur est commuu avec les 

 Iilcrevisses [Astacus]." Tiiis passage is inexplicable to nie, but seems to sliow a complete 

 misconception of what Hagen means by the hooked legs of Cambarus. With regard to 

 the second point, — Hageu's division of Cambarus into species, most of which, according 

 to Brocchi, should be considered as simple varieties, — it mu§t be admitted that there 

 will always be a difference of opinion concerning the amount of variation necessary 

 to warrant the erection of species ; but I think that any zoologist, with ample material 

 before him, will admit the justice of Hagen's principle of division. Brocchi's censure 

 of Hagen's work is wholly unmerited, and springs from ignorance of the subject umler 

 discussion. That the author does not understand the phenomenon of two forms of the 

 male Cambari is shown on page 28. Tiie final objection to Hagen's principle of classifi- 

 cation, tliat it would lead to the breaking up of tlie Euro])ean Astacus flnviatilis of 

 authors into several species, is of no weight, since the dismeiubcrnient of tiiat species 

 was brought about long ago on other grounds than the character of the male appen- 

 dages. Brocchi's Astacus fiaviatilis, from Vaucluse (PI. XII. figs. 12, 1.3), is A. pallipes 

 Lereboullet. 



1876. S. A. Forbes, iu his " List of Illinois Crustacea, with Descriptions of New 

 Species " (Bull. 111. Mus. Xat. Hist., No. I. pp. 3-25), records, with annotations, C. acutus 

 Gir., C. virilis Hag., C. projnnquus Gir., C. immunis Hag., C. obesus Hag. ; also, on the 

 authm-ity of Dr. Hagen, C. troglodytes and C. iilacidus. The second form of the male 

 C. immunis Hag. is described for the first time. Three new species, described by W. F. 

 Bundy, are included in the list : C. Stygius, from Lake Michigan ; C. Wisconsincnsis, 

 from Normal, 111., and Eacine, Wis. ; and C. gracilis from Illinois and Wisconsin. In 

 an appendix to tlie list, Mr. Bundy describes two more new species of Cambarus from 

 without the limits of the State of Illinois ; viz. C. Sloanii from Southern Indiana and 

 Kentucky, and C. debilis from Wisconsin. 



Of Bandy's species I have seen types (in the Museum of Comparative Zoology) of 

 C. Wisconsincnsis, C. gracilis, C. Sloanii, and C. debilis. C. gracilis and C. Sloanii are 

 good species. C. Wisconsincnsis appears to be the same sjiecies as Hagen's C. placidus 

 (= C rusticus, var. ?). C. debilis is the second form of the male of C. virilis Hag. 

 C. Stygius, according to Bundy in a later paper, closely resembles C. acutus, but differs in 

 the shorter chela3, which resemble those of C. 2}ropinrjuus. All of the specimens of this 

 species seen by Bundy were mutilated, the fourth pair of legs being lost. 



1877. Mr. Bundy (" On the Cambari of Northern Indiana," in Proc. Acad. Nat. Sci. 

 Pliila., 1877, pp. 171-174) records C. immunis Hag., C. obesiis Hag., C. virilis Hag., and 

 C. jyropinrpius Gir., from Northern Indiana ; redescribes C. Sloanii from Southern In- 

 diana and Kentucky ; and describes a new species, C. spinosus, from near Pome, 

 Georgia. Through the courtesy of Mr. P. II. Uhler, the Museum of Comparative 



