CAMBAEUS. 11 



of the previously described species were examined by Dr. Hagen in the 

 course of the preparation of his monograph; viz. G ClarkU Gir., G. propin- 

 quus Gir., G montanus Gir., C. rnslicus Gir., G. longidus Ciir.. G Bartomi (Fab.), 

 and G. affinis (Say). Hagen proved the correctness of Girard's determi- 

 nation of Fabricius's and Say's species. Of Girard's new species, G. monianus 

 appeared identical with G. Bartomi, and C. longulus was deemed by Hagen 

 to be an accidental variety of G Bartomi. A thorough search for Girard's 

 types in the Smithsonian Institution made by myself in December, L882, 

 discovered one mure species. ('. Pcalei, which proved to be large speci- 

 mens, male and female, of G affinis (Say). These (and Astacus GambeUi 

 in the Philadelphia collection) are the only types of Girard's species now- 

 existing. 



There are, however, in the Museum of the Academy of Natural Sci- 

 ences of Philadelphia eight species labelled with Girard's names (followed 

 in most cases by a question-mark) and the localities quoted by Girard. These 

 specimens may be considered of almost equal authority with type speci- 

 mens. They are the following: G.Pealei? Criistieus ? G. montanus? G. propin- 

 quus ? G acuHssimus ? C Diogenes? C. robustus, and G. Blandingii. C.Pealeif 

 is the same as the typical G Pealei in the Smithsonian Institution (= G affi- 

 nis). G rusticus? and G. monianus? are identical with the types of the same 

 name examined by Hagen. " G propinquus ? Garrison's Creek, Sackett's 

 Harbor," is C. obesus Hag., and " G. Diogenes ? District of Columbia," is 

 ( '. propinquus as determined from the type examined by Hagen. That an 

 accidental transposition of labels has here taken place is evident from the 

 localities given on the labels (C propinquus is not found in the District of 

 Columbia), and from the account of the characteristic habits and coloration 

 of C. Diogenes given by Girard. Through this misplacement of labels, and 

 through his ignorance of the peculiar habits of the "chimney crayfish," 

 Hagen failed to see the identity of his own C. obesus and Girard's G.Diogenes. 

 C. acutissimus ? is the young of C.acutus; G. robustus may be considered a 

 variety of C. Bartomi; C. Blandingii is not Harlan's species, but the one after- 

 wards described by Lc Conte as A. troglodytes. There remain in Girard's list, 

 to lie determined without the aid of types or authoritative specimens, the 

 following : G. acutus Gir., G. peUucidus (Tellk.), C. Carolinus Erichs., G. pusillus 

 (RaL), G Nebrascensis Gir. G pusillus, whether if be the same as Rafinesque's 

 species or no, is probably a small form of G Bartomi ; G Nebrascensis, 1 think, 

 may be a variety of C. Diogenes. 



