6 A REVISION OF THE ASTACIDA 
abdominal appendage of the male Cambarus robustus (Pl. XL 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 reeard 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 branchize, 
and this he has not been able to verify ! He goes on to say (p. 26): “Si Von prend, par 
exemple, le earactére tiré de la présence d'un ongle @ la troisiéme et quatriéme paire de 
pattes, je ferai observer qu’une seule espéce Cambarus, le Cambarus acutus, présente cet 
appendice & la troisitme et quatriéme paire de pattes; tous les autres ont seulement 
les quatriéme et cinquiéme paires unguiculées, 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 zodlogist, 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 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 fluviatilis of 
authors into several species, is of no weight, since the dismemberment of that species 
was brought about lone ago on other grounds than the character of the male appen- 
dages. Brocchis Astacus fluviatilis, from Vaucluse (PI. XII. figs. 12, 13), is A. pallipes 
Lereboullet. 
1876. §. A. Forbes, in his “ List of Illinois Crustacea, with Descriptions of New 
Species” (Bull. Tl. Mus. Nat. Hist., No. I. pp. 8-25), records, with annotations, C. acutus 
Gir, C. virilis Hag., C. propinquus Gir. C. immunis Hag., C. obesus Hag. ; also, on the 
authority of Dr. Hagen, C. troglodytes and C. placidus. 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. Wisconsinensis, 
from Normal, Ill, and Racine, Wis.; and C. gracilis from Illinois and Wisconsin. In 
an appendix to the list, Mr. Bundy describes two more new species of Cambarus from 
without the limits of the State of TMlinois; viz. C. Sloanit from Southern Indiana and 
Kentucky, and @ debilis from Wisconsin. 
Of Bundy’s species I have seen types (in the Museum of Comparative Zodlogy) of 
C. Wisconsinensis, C. gracilis, C. Sloanti, and C. debilis. C. gracilis and C. Sloanw are 
good species. C. Wisconsinensis appears to be the same species as Hagen’s C. placidus 
(= ©. rusticus, var.?). ©. 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 chelz, which resemble those of ©. propinguus. 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. 
Phila, 1877, pp. 171-174) records C. immunis Hag., ©. obesus Hag, C. virilis Hag., and 
C. propinqguus Gir., from Northern Indiana; redescribes C. Sloanii from Southern In- 
diana and Kentucky; and describes a new species, C. spinosus, from near Rome, 
Georgia. Through the courtesy of Mr. P. R. Uhler, the Museum of Comparative 
