CAMBAEUS. 11 



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

 course of the preparation of his monograph ; viz. C. Clarkii Gir., C. propin- 

 qnus Gir., C. monianus Gir., C. nisficus Gir., C. lonr/idiis Gir., C. Bartonii (Fab.), 

 and C. iiffinis (Say). Hagen proved the correctness of Girard's determi- 

 nation of Fabricius's and Say's species. Of Girard's new species, C. montanus 

 appeared identical with C. Bartoml, and C. hngulus Avas deemed by Hagen 

 to be an accidental variety of C. Bartonii. A thorough search for Girard's 

 types in the Smithsonian Institution made by myself in December, 1882, 

 discovered one more species, C. Pcalei, which proved to be large speci- 

 mens, male and female, of C. affiuis (Say). These (and Astacus Gamhelii 

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

 existing. 



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

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

 in most cases by a question-mark) (aid the localities quoted hy Girard. These 

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

 mens. They are the following: CPealci? C.rmticits? C. montanus? C. propin- 

 qiius ? C. acutissimus ? C. Diogenes ? C. rodusins, and C. Blandingii. C. Pealei ? 

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

 nis). C. rusticus? and C. montanus? are identical with the types of the same 

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

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

 C. 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. propinquns is not found in the District of 

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

 of C. Diogenes given by Gii'ard. 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 C. Diogenes. 

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

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

 wards described by Le Conte as A. troglodytes. There remain in Gii-ard's list, 

 to be determined without the aid of t3q)es or authoritative specimens, the 

 following: C. acutus Gir., C. pellucidus (Tellk.), C. Carolinus Erichs., C. piisillus 

 (Raf.), C. Nebrascensis Gir. C. pusillus, whether it be the same as Rafinesque's 

 species or no, is probably a small form of C. Bartonii ; C. Nebrascensis, I think, 

 may be a variety of C. Diogenes. 



