MR. HALDEMAN'S DESCRIPTIONS OF COLEOPTERA. 109 



the elytra, and widest anterior to the base, the angles of which are acute and as much 

 produced as in atomaria : scutel punctured and pubescent, rather smaller than in 

 atomaria : elytra short, densely punctate and pubescent, apex faintly flavous, outline 

 as in atomaria : abdomen pubescent, scarcely exposed ; beneath black. 



T. ASPERA Hald. Elongate oval, subparallel, black, pubescent, surface covered 

 with numerous rounded elevated points ; antennae shining black, feet pale fuscous. 

 \ lin. long. Hab. Middle States and Lake Superior. Form o^ pygmcea Er. — Gillm. 

 pi. 4. fig. 5, but rather more robust : head, pronotum and elytra, slightly pubescent 

 and asperate : prothorax a little dilated posteriorly, basal angles acute, and produced 

 but little : elytra with the sides slightly convex ; apex faintly fuscous, separately and 

 obtusely rounded. From the rarity of the union of black antennae and pale feet in 

 this genus, it is possible that this species may be identical with sericans Er. — Gillm. 

 p. 51, pi. 4, fig. 3 ; which has these characters, and besides a wide distribution in 

 Europe and Siberia, is stated to occur at Baltimore. 



PTENIDIUM Erichson. 



P. TERMiNALE Huld. Polishcd black, sparsely pubescent ; antennae, feet, and apex 

 of the elytra, flavous. I lin. long. Hab. Pennsylvania in May. Outline of 

 Imngalum Er. — Gillm. p. 8, fig 4, but the apex of the elytra is less suddenly 

 contracted and more obtusely rounded. Head with a few hairs; a lateral fovea in 

 front of the base of the antennae ; eyes coarsely reticulate : prothorax impunctate, the 

 anterior and posterior width subequal ; basal angles obtusely rounded ; anterior 

 angles advanced and obtuse : elytra sparsely and faintly punctate. 



The date of the genus Trichopteryx is, according to Gillmeister, 1818 ; Allibert, 

 (Revue Zool. 1847, p. 188,) 1808 ; and Erichson in Agassiz' Nomenclator, 1826, the 

 last being probably correct, but in either case it takes precedence of Ptilium 

 Gyllenhal, the date of which seems to be 1827, having been first characterized by 

 this author in an appendix to his Insecta suecica, although previously known as an 

 unrestricted catalogue name. Gillmeister has divided the family (or genus, as he 

 considers it,) into five groups, of which he gives the characters, and which nearly 

 correspond with the following genera : 



Trichopteryx Kb. Er. — Gillm. §i. p. 41, pi. 3, 4. 



Ptinella Motchulshj. 



" ii. 



" 57, 



" 5, 



Ptilium Gyll Er. 



" iii. 



" 67, 



" 6. 



Ptiliola Hald. 



" iv. 



" 76, 



" 7. 



Ptenidium Er. 



" V. 



"82, 



'• 8. 



