OBSEBVATPONS ON THE ASTACIDJ3 IN THE UNITED 

 STATES NATIONAL MUSEUM AND IN THE MUSEUM OF 

 COMPAEATIVE ZOOLOGY, WITH DESCRIPTIONS OF NEW 

 SPECIES. 



By Walter Faxon, 



Assistant in charge of Mollusca and Crustacea, Museum of Comparative Zoology, 

 Cambridge, Massachusetts. 



Since the publication of my "Notes on North American Crayfishes'' 

 in 1890, a good deal of material has accumulated in the United Slates 

 National Museum and in the Museum of Comparative Zoology. The 

 first part of the present article embodies the results of an examination 

 of this material. 1 



The second part relates to the crayfishes of the Southern Hemi- 

 sphere — the Parastacince. After the publication of Part I of my 

 "Revision of the Astacidre," which treated of the Northern Hemi- 

 sphere genera, Cambarus and Astacus, I hoped to get together a col- 

 lection of the Parastacine crayfishes that would enable me to issue the 

 second part of the revision in a shape similar to the first part. Disap- 

 pointed in this nope, I have decided to include in this paper such results 

 as I could obtain from a study of the Parastacince in the two museums 

 above named. Thanks to Mr. Charles C. Chilton, of Christchurch, 

 New Zealand, my series of New Zealand crayfishes is ample, but lack 

 of adequate material from Australia, Tasmania, and South America 

 precludes a satisfactory revision of the Parastacince as a whole. 



Six new species and three new subspecies of Cambarus are described 

 and figured in this paper. Of these, five belong to the United States, 

 four to Mexico. Five new species of Parastacus are also described and 

 figured — two from Uruguay, two from Chile, and one ostensibly from 

 Mexico. 



'Anyone who undertakes the perplexing study of the North American crayfishes 

 should have at hand the following works: 1. Monograph of the North American 

 Astacidue. By Hermann A. Hagen. 111. Cat. Mus. Comp. Zool., No. 3 [Mem. Mus. 

 Comp. Zool., II, No. 1], 1871. 2. A Revision of the Astacidse. Parti. The Genera 

 Cambarus and Astacus. By Walter Faxon. Mem. Mus. Comp. Zool., X, No. 4, 1885. 

 3. Notes on North American Crayfishes — Family Astacidte. By Walter Faxon. 

 Proc. U. S. Nat. Mus., XII, pp. 619-634, 1890. 4. The present article. In these 

 works all the North American crayfishes are described and many of them figured. 



PROCEEDINGS U- S. NATIONAL MUSEUM, VOL. XX-NO. 1136. 



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