ASTACIDiE. G5 



Cat. No. 19 J:, Lake Superior, L. Agassiz. Male Form I. and 11. Fom. 

 Spec. 12.* 



Cat. No. 203, Lake Superior, L. Agassiz. Male Form II. Fein. 

 Spec. 6. 



Cat. No. 1828, Lake Winnipeg, British America, Mr. S. H. Scudiler. 

 Male. Feni. Spec. 12.* 



Cat. No. 1829, Red River, British America, Mr. S. H. Scudder. Male. 

 Fem. Spec. 12.* 



Cat. No. 1830, Saskatchavan River, British America, Mr. S. II. Scud- 

 der. Male. Fem. Spec. 4. 



Cat. No. 196, Quincj, 111., Dr. Watson. Male. Fem. Spec. 12.* 



Var. A. 



Cat. No. 1831, Osage River, Dr. StoUey. Male Form II. Fem. 

 Spec. 12.* 



Cat. No. 1832, Osage River, Dr. Stolley. Male Form II. Fem. 

 Spec. 12.* 



Cat. No. 192, Osage River, Dr. Stolley. Male Form I. Spec. 1. 



Cat. No. 171, Burlington, Iowa. Male Form I. Fem. Spec. 3. 



Cat. No. 200, Texas, Dr. Stolley. Male Form I. Fem. Spec. 12.* 



Cat. No. 207, Texas, Dr. Stolley. Male Form I. Fem. Spec. 4. • 



Cat. No. 1833, Davenport, Iowa. Male Form L Fem. Spec. 3. 



Dry Spec, Lake George, L. Agassiz. Male. Spec. 1. 



17. Ca3ibarus placidus Ilagen. 



Figures on PI. I. anfl III. 

 First abdominal legs of the male : 



first form, fig. 76 in front; fig. 77 outside. 



not articulated second form, fig. 78 in front; fig. 79 outside. 

 Antennal lamina, fig. 158, n; epistoma, 6 ; spine of tlie second joint of the exterior antenna, c. 



This species is intermediate between C. vinlis and C. juvenilis. It 

 lives in the same localities, — Texas, Temicssee, and Quinc}^, Illinois. 

 In its general form, more cylindrical thorax, smaller and more deeply 

 sulcated rostrum, with the margins more thickened, it resembles C juve- 

 nilis ; the abdominal legs of the male (Forma I. and II.) are very sim- 

 ilar to those of C. rin'lis, though in one male the posterior hook is. 

 slightly evident ; nevertheless, the forehands are very dissimilar, more 

 .slender, much longer, not so much punctated, especially on the finger.s, 

 which are flattened ; the inner marcrin of the hands is verv little tuber- 

 culated ; the fingers are more separated at the base, while the external 

 one is not barbated ; a few females from Tennessee have little hairs, 

 and are scarcely tuberculated at the inner margin, though sometimes 

 they are much elongated ; the carpus is bispinose beneath, the spines 

 often being very obtuse, especially the interior ones ; the biseriated 



