632 NORTH AMERICAN ASTACID^ — FAXON. 



Labette County, Kansas. W. S. Newlon (M. C. Z.). Five males, form 

 I; five males, form II; seven females. 



This species much resembles G. virilis, especially the form called 

 variety A by Dr. Hagen. It differs in the shape of the first abdominal 

 appendages of the male. In G. na'is the rami of these appendages are 

 shorter and more strongly curved than in G. virilis, but not so much 

 curved as in G. immunis. The areola is narrower than in C. virilis. 

 The first abdominal appendages are very like those of G. palmeri Fax., 

 as far as can be seen by a comparison of the second-form males alone ; 

 but the areola is not obliterated in any part of its course in G. na'is 

 and the rostrum is more tapering than in G. palmeri. 



Cambarus immunis Hag. 



Additional localities: Wabash Eiver, New Harmony, Indiana, D. S. 

 Jordan (U. S. F. C.) ; Lafayette, Indiana, H. L. Osborn (M. C. Z.). 



Cambarus immunis spinirostris Fax. 



Additional locality : Ward's Creek, Shawnee County, Kansas. F. 

 W. Cragin and J. B. Fields (M. C. Z.). 



When I described this variety in 1881, I had not seen the first form 

 of the male, which is included among the specimens collected by Messrs. 

 Cragin and Fields. The lateral spines of the rostrum are distinct, as 

 in the second-form male and in the female ; the seta3 on the second pair 

 of legs are well developed; the first abdominal appendages are shaped 

 exactly as in the first form male of the typical G. immunis. 



Cambarus rusticus Gir. 



Additional localities: Maramee River, Dent County, Missouri, R. E. 

 Call (M. C. Z.); Harpeth River, Franklin, Tennessee, Gilbert and 

 Swan (U. S. K M.) ; Osage River, La Cygue, Kansas (M. C. Z.). All 

 these are similar to the form placidus Hag. 



Cambarus spinosus Buudy. 



Additional locality : Tar River Rocky Mount, North Carolina. D. S. 

 Jordan (IT. S. F. C). 



Cambarus hylas, sp. nov. 



Male, form II. — Rostrum broad, excavated, margins thickened, some- 

 what convergent from the base to the acute lateral spines ; acumen of 

 moderate length. Post-orbital ridges ending anteriorly in an acute 

 spine ; carapace punctate, with a small lateral and a branchiostegian 

 spi'ie; anterolateral margin notched but not furnished with a sub- 

 orbital spine ; posterior segment equal in length to half the distance 

 from the end of the rostrum to the cervical groove; areola of moderate 

 width, punctate. Abdomen longer than the cephalothorax ; basal seg- 

 ment of the telson bispiuous on each side of the posterior border. 



