6 A REVISION OF THE ASTACIDJE. 



abdominal appendage of the male Cambarus robust us (PI. XIII. fig. 15), and criticises 

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

 genus into upwards of thirty species, based chiefly on the 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 the genus, only 

 one seems to him to be of any importance, namely, the absence of the posterior branchiae, 

 and this he has nut been able /•> verify ! He goes on to say (p. 26) : " Si Ton prend. par 

 exemple, le earactere tire de la presence d'un ongle a la troisieme et quatrieme paire de 

 pattes, je ferai observer qu'une seule espece Cambarus, le Cambarus aeutus, pre"seute cet 

 appendice a la troisieme et quatrieme paire de pattes; tous les autres ont seulement 

 les quatrieme et cinquieme paires unguiculees, caractere qui leur est commun avec les 

 Ecrevisses [Astacus]." This passage is inexplicable to me, but seems to show a complete 

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

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

 to Brocchi, should be considered as simple varieties, — it must 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, witli 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 under 

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

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

 cation, that it would lead to the breaking up of the European Astacus flwciatilis of 

 authors into several species, is of no weight, since the dismemberment of that species 

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

 dages. Brocchi's Astacus jtuviatilis, from Vaucluse (PI. XII. figs. 12, 13), is A. pallipes 

 Lereboullet. 



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

 Species" (Bull. 111. Mus. Xat. Hist., No. I. pp. 3-25), records, witli annotations, G. aeutus 

 Gir., G. riri/is Hag., G. propinqmhs Gir., C. immunis Hag., G. obesus Hag.; also, on the 

 authority of Dr. Hagen, G. troglodytes and C. placidus. The second form of the male 

 C. i in in n n is 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. Wisconsinensis, 

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

 an appendix to the list, Mr. Bundy describes two more new specie's of Cambarus from 

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

 Kentucky, ami G. debilis from Wisconsin. 



of Bundy's species 1 have seen types (in the Museum of Comparative Zoology) of 

 C. Wisconsinensis, G. gracilis, C. Sloanii, and C. debilis. C. gracilis and C. Sloanii are 



! species. C. Wisconsinensis appears t" be tin' same species as Hagen's C. plact 



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

 U. Stygius, according to Bundj in a. Liter paper, closely resembles C. aeutus, but differs in 

 the shorter chelae, which resemble those of C. propinguus. All of the specimens of this 

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



1*77. Mr. Bundy (" On the Cambari of Northern Indiana," in Proc. Acad. Xat. Sci. 

 Phila., I S 7 7 , pp. 171-171) records ('. immunis Hag.. < '. ,ibcsus Hag., C. riri/is Hag., and 

 C propinguus Gir., from Northern Indiana; redescribes 0. Sloanii from Southern In- 

 diana and Kentucky; and describes a new species, ('. spinosus, from near [tome, 

 Georgia, Through the courtesy of Mr. i". \l. Uhler, the Museum of Comparative 



