no. 1136. OBSERVATIONS ON THE ASTACID^E— FAXON. 6"49 



CAMBARUS MEXICANUS Erichson. 



Mirador and Santa Maria, Mexico (Coll. U.S.N".M.). The annulus ven- 

 tralis of the female forms a prominent tubercle, with perpendicular 

 posterior wall, facing a roundish tubercle arising from the posterior 

 thoracic segment. The anterior and ventral sides of the annulus are 

 divided by a longitudinal groove which is bounded on each side by a 

 rather prominent lip. 1 



CAMBARUS GRACILIS Bundy. 



Six young specimens from Day Brook, Jasper County, Missouri, Miss 

 Buth Hoppin, probably belong to this species. (No. 4341, Mus. Comp. 

 Zool.) 



GROUP III. (Type, Asiacus bartonii Fabricins.) 



Third segment of third pair of legs hooked. First pair of abdomi- 

 nal appendages of male thick, the inner and outer parts both terminat- 

 ing in a short recurved tooth. 



CAMBARUS BARTONII (Fabricius). 



North Adams, Berkshire County, Massachusetts (Coll. Mus. Comp. 

 Zool.); Westmoreland County, Pennsylvania; Waynesville, Haywood 

 County, North Carolina; Boan Mountain, ^Sorth Carolina, from an alti- 

 tude of 6,000 feet (Doctor C. H. Merriam); Warren County, Ohio; 

 Albany, Clinton County, Kentucky; Claiborne, Monroe, and McMinn 

 Counties, Tennessee (Coll. U.S.N.M.) ; caves in Lawrence and Orange 

 Counties, Indiana ( W. P. Hay, Proc. IT. S. Nat. Mus., XVI, 1893, p. 286). 



CAMBARUS BARTONII ROBUSTUS (Girard). 



Oneida Creek, Peterboro, Madison County, New York, G-. S. Miller, 

 jr. (No. 4329, Mus. Comp. Zool.). According to Doctor B. W. Shufeldt, 2 

 Gambarus bartonii robustus in Montgomery County, Maryland, builds 

 mud towers at the mouth of its burrow similar to those of G. diogenes. 

 A figure of one of these towers, or "chimneys," from a photograph, is 

 given in Snufeldt's article. 



CAMBARUS BARTONII LONGIROSTRIS Faxon. 



Two males and one female from Will's Creek, Pollard, Escambia 

 County, Alabama (Coll. U.S.N.M.). The suborbital angle is sharply 



1 In the artificial key to the species of Group II on p. 48 of my "Revision of the 

 Astacidte/' C. mexicanus is distinguished from C. simulans by the moderate width of 

 the areola contrasted with the narrow areola of C. simulans. In fact, the areola is 

 very narrow in both species (it is too broad in the figure of C. simulans on pi. i of 

 the "Revision"). The distinction should have been drawn from the rostrum and 

 chelae. The rostrum is nearly plane above in C. mexicanus, deeply hollowed out in 

 C. simulans; the chela is much narrower, and more heavily and closely tuberculated 

 in C. mexicanus than in the latter species. 



2 The Observer, VII, No. 3, p. 88, March, 1896. 



