NATURAL SCIENCES OF PHILADELPHIA. 365 



Body black, shining, prothorax as in the preceding, elytra at humeri dis- 

 tinctly wider than base of prothorax, intervals with confused fine punctures. 

 Long. 3-5 — 4-5 mm. Southern States, 4 specimens. (Rather stouter in form 

 than the preceding, and resembling almost exactly B. f a r e u s, but quite dif- 

 ferent by the antenna and beak.) 27. ibis. 



Body brown, shining, prothorax longer than in the preceding and less 

 rounded on the sides, more densely punctured with a faint dorsal carina ; 

 elytra at humeri distinctly wider than base of prothorax, intervals wtth con- 

 fused fine punctures. Long. 3-5 mm. Georgia and Illinois, 4 specimens. 



28. s c o 1 p ax Say. 

 Bibliography. 



B. carinulatus Lcc. Proc. Ac. Nat. Sc, Phila., 1858, 79. 



B. transversus Say. Cure. 18 ; ed. Lee. i, 282. 



B a e r e u s Sch. Cure, viii, 141. 



B. interstitialis Say. Cure. 18 and 26 ; ed. Lee. i, 282, 295 ; Journ. 

 Acad. N. S. Ph. iii, 314; ed. Lee. ii, 176; Sch. iii, 684 ; viii, 149. In well pre- 

 served specimens small scale-like hairs are perceived in the rows of punc- 

 tures on the elytral intervals, 



B. m a c e r Lee. Rep. Pac. R. R. Expl. xi, MS. 58. 



B. striatus Say. Cure. 17 ; ed. Lee. i, 281. 



B. den s us Lee. Proc. Ac. Nat. Sc, Phila., 1859, 79. 



B. n igri nu s Say. Cure. 31 ; ed. Lee. i, 295. Sch. Cure, iii, 691 ; viii, 154. 



B. seriatus Lee. Rep. Pac. R. R. Expl. xi, MS., 58. 



B. trinotatus Say. Cure. 7 ; ed. Lee. i, 280 ; vestitusX Sch. Cure, iii, 718. 



B. mucoreus Lee. Proc. Ac. Nat. Sc, Phila., 1858, 79. 



B. s c ol o p ax 5(/y. Cure. 26 ; ed. Lee. i, 295 ; Sch. Cure. iii. 699. I do 

 not know for what reason Schdnherr has referred this species to his first divi- 

 sion ; Boheman, in the description, mentions the antenna as minus erassx, 

 which in fact tiiey are. 



Speeies iinknown to me. 



B. T-signum Sch. Cure, viii, 154. 



B. anthraclnus Sch. Ibid, iii, 727. Seems to be near 28. ibis Lee. 

 B. confertus Seh. Cure, iii, 728. 

 B. californicus Motseh. Bull. Mosc. 1845, ii, 372. 



B. pubescens Uhler, Proc. Ac. Nat. Sc, Phila., 7, 417 belongs to Cen- 

 trinus and is C. p i s t o r Sch. = Balaninus pistor Germ. 



The GYEINID.E of America, north of Mexico. 

 BY JOHN L. LE CONTE. 



Species of this family are found in every part of the United States and con- 

 tiguous northern regions, usually in large colonies ; from their whirling mo- 

 tion of the surface of the water they are popularly known as whirligigs, and, on 

 account of the agreeable fragrant odor of some of the species, as apple-bugs. 



There is a remarkable uniformity of appearance in the species of each genus, 

 which renders their definition and recognition somewhat difficult ; for this 

 reason, notwithstanding the very curious structural characters displayed in 

 their organization, which are detailed in all sj-stematic works, they are not 

 favorites with collectors, and many of our species have remained unnamed. 



Three genera are represented in our fauna : 



Last ventral segment depressed, rounded at tip : 



Scutellnm distinct: labrura transverse Gj-rinus. 



Scutellum invisible; labrum transverse D i n e u t u s. 



Last ventral segment elongated, conical : 



Scutellum invisible ; labrum prominent Gyretes. 



1868.] 



