COLEOPTERA. 455 



of the presternum is prolonged, laminiform, flattened, and received 

 into an emargination of the mesosternum. The body is oval, and 

 rounded at both ends; the lateral edges of the thorax are strongly 

 arcuated, and simply narrowed near the posterior angles. The an- 

 tennas are slightly and gradually enlarged towards the extremity(l). 



Machla, Herbst. 



The antennae terminated by a little globuliform club composed of 

 the three last joints; they can be received into cavities underneath 

 the sides of the thorax, which are extremely thick and rounded(2). 

 In 



Scotinus, Kirb. 



The antenna; are also terminated by a little club, but in which the 

 two last joints are almost confounded; they are not susceptible of 

 being received into particular cavities. The thorax is dilated be- 

 fore(3). 



Sometimes the thorax is almost trapezoidal, gradually arcuated 

 throughout the whole extent of its lateral edges, and is not abruptly 

 narrowed posteriorly. The mentum covers the base of the maxillae. 



The two last joints of the antennae are united in a small club. Such 

 are the 



Asida, Lat.(4) 



Next come Blapsides, with an oval and slightly elongated body, 

 in which the lateral curve of the elytra is narrow, and extends but 

 little underneath ; in which the thorax is always transversal, al- 

 most square or trapezoidal, and the lateral edges arcuated; and 

 which are still more remarkable for the sexual difference in their 

 tarsi, the two or four anterior ones being most dilated in the 

 males(5). 



These Insects frequent sandy localities. The two anterior tibiae 

 are usually wider, dilated triangularly at the extremity, and fitted for 

 digging. 



(1) Pimelia dentipes, Fab.; Platynotus reticulatus, ejusd. ; Pimelia obscura, 

 Oliv. ; Insects from the Cape of Good Hope. 



(2) Platynotus serratus, Fab. 



(3) Scotinus crenicollis, Kirb., Lin. Trans. XII, xxi, 14, a subgenus peculiar to 

 South America. 



(4) Lat., Gener. Crust, et Insect, II, p. 155. See the Catalogue, &c, of Dejean, 

 p. 65. The Platynotus undatus of Fabricius differs but little from the A. grisea. 

 That author is, I think, mistaken as to its habitat. Plat, laevigatus, Id. 



(5) The inferior surface of these tarsi is usually silky or furnished with a brush. 



