NATURAL SCIENCES OF PHILADELPHIA. 373 



is not mentioned by the authors above cited, nor by Redtenbacher ; but atten- 

 tion is called to it in the description of Thomson, Skandir. Coleoptera, ii, 117_ 

 23. G. rockinghamensis Zimm., MS. Dr. Ziramermann mentions in 

 his MS. that he found this species in schools of several thousands, in ponds 

 at Rockingham, North Carolina. I have translated the description from his 

 notes. 



Species not identified. 



(Jr. impressicollis Kirby, Fauna Bor. Am. iv, 79. Mr. Adam White, 

 B. M. Cat. 45, refers this to G. borealis Aube, but the great size, unless an 

 error of print, (4 lines, = 8-3 mm.) renders such reference very improbable. 



G. Sayi Aitb^ Hydroc. 698. See remarks under No. 17. 



G. fuscipes Motsch. MwW. Mosc. 1859, ii, 173. California; perhaps G. 

 cohsobrinus Lee* 



Gyretes BruU6. 



1. G. s i n u a t u s, elongate oval, very convex, dark bronzed, very shining ; 

 sides of prothorax and elj'tra densely punctured and pubescent, punctures 

 reaching the suture; tip of elytra broadly and obliquely truncate, outline of 

 the truncation very slightly but distinctly sinuate, outer angle distinct, 

 slightly prominent, infiexed margins ferruginous; body beneath and legs 

 ferruginous, breast and base of abdomen darker. Long. 6 mm. Lee. Anu. 

 Lye. Nat. Hist., New York, v, 210. 



Abundant in the Colorado River, near Fort Yuma, California. 



2. G. c o m p r e s s u s, still more elongate, and more convex than the pre- 

 ceding, and more narrowed in front than behind, dark bronzed, shining ; sides 

 of prothorax and elytra densely punctured and pubescent, punctures not 

 quite reaching the suture ; tip broadly and obliquely truncate and very feebly 

 sinuate, outer angle obtuse, distinct, slightly prominent, inflexed margins 

 black ; body beneath dark brownish red. feet and tip of abdomen paler. Long. 

 675 mm. Lee, New Spec, North Am. Col,, (Smith's Inst.) 23, 



One specimen collected at Quiacy, Illinois, by Mr. Willcox. 



Notes on the Species of AGONODERUS, BRADYCELLUS and STENOLOPHUS in- 

 habiting America north of Mexico. 



BY JOHN L. LE CONTE, M. D. 



The final demolition of the genus Acupalpus Dej. seems to have been accom- 

 plished by Baron Chaudoir, in his recent notes upon North American Cara- 

 bid;Te,-j- by the reference of most of the species contained in my third division 

 of StenolophusJ to A(jonoderus. In fact, his suggestion is so perfectlj' natural, 

 that it is strange that the resemblance in form and sculpture, and in the pro- 

 portion of the joints of the hind tarsi, with the absence of sexual characters in 

 the front tarsi, did not lung since cause these species to be placed in the proper 

 position to which he has assigned them. 



In reviewing the specimens of my collection with the aid of the remarks of 

 my learned friend, I have found such resemblances in form between the species 



* Mr. Uhler has sent me a portion of a large school of Gyrinus, collected in Charles 

 Kiver, near Cambridge, Mass., which shows that in some eases at least the speeie.s do not 

 live apart. An examination of all the individuals captured has given me the following 

 results : — 



G. 1 imbat u s, 4cr, 5?. G, fraternus, 2cf, 2$. 



G. d i c h r o u s, 5cf (59. G. p ici p e s ? uace), 5cf 39. 



G. confinis, \2^ 7$. G.lugens, 18cf 4?. 



I have observed at Lake Superior, however, that the species are generally not found 

 intermixed, 

 t Uevue et Mag. de Zoologie, 1808. 

 J Vide List of Coleoptera, North .\m., p. 13. 



1868.] 



