234 PROCEEDINGS OP THE ACADEMY OF 



TRYPOPITYS Redt. 



la this genus the thorax is deeply excavated beneath for the reception of 

 the head, and the pectoral excavation is prolonged into the metasternum, as 

 in A n o b i u m, but the autennae are serrate, with the second joint shorter 

 than the third ; the third to the seventh are triangular, and gradually a little 

 longer; the eighth to the tenth become gradually less triangular, they are 

 nearly equal in length, and each is a little longer than the seventh ; the 

 eleventh is still longer, and somewhat pointed. The first ventral segment 

 is bounded behind by a distinct suture, but the other sutures are obliterated. 



The last joint of the labial palpi is triangular, and broadly truncate. 



Our two species may be distinguished thus : 



Punctures of elytral striae large, quadrate s e r i c e u s. 



Punctures of elytral striae smaller, oblong punctatus. 



1. T. sericeus Lee, Say's Ent. Writings, ii. 280. Xyletinus sericeus Say, 

 Journ. Acad. Nat. Sci., v. 172, (ed. Lee, 1. c, sup.) 



Atlantic States ; generally diffused. 



2. T. punctatus Lcc, Col. Kansas, (Smithsonian Contr.,) p. 13. 

 New Mexico, near Santa Fe. 



PETALIUM Lee, Class. Col. N. Am., 204, (1862.) 



Body elongate, prothorax closely united with the trunk, excavated beneath 

 for the reception of the head, which is small and convex, both above and be- 

 neath. The eyes are large and not very convex ; the antennas are half as 

 long as the body ; the first joint is long and moderately tbick, the second 

 joint is nearly as wide as the first, and about as long as its width ; the third 

 and fifth are transverse and triangular ; the fourth, sixth and seventh are nar- 

 rowed and smaller, the eighth is still smaller, and only visible with a very 

 high power ; the ninth is triangular, and as long as the third and eighth in- 

 clusive ; the tenth is similar, and equal to the ninth ; the eleventh is a little 

 longer, oval and somewhat poinded. The last joint of the palpi is fusiform 

 and acute. 



The prosternum is extremely short, the anterior coxa? are conical, and rise 

 perpendicularly, leaving a wide intervening cavity. The mesosternum is 

 deeply excavated longitudinally, and is overshadowed by the metasternum so 

 as to be visible only on dissection. The metasternum is long, deeply sulcate 

 at posterior half, prolonged in front into a very large, slightly convex lobe, 

 which extends over the mouth in repose ; towards the sides the anterior por- 

 tion of the sternum is declivous, and hollowed transversely for the reception 

 of the middle feet; there is a deep transverse excavation for the reception of 

 the middle tarsi each side of the metasternal lobe. The first ventral segment 

 is short, not excavated for the reception of the hind feet ; the second segment 

 is as long as the three following united. The fec-t are moderate, thighs rather 

 long, tibia; slender, tarsi short, stout, moderately dilated. The epipleurae are 

 hollowed out below the humeri for the reception of the middle knees, and fo- 

 veate about the middle for the hind knees. 



I have been thus particular in the description of this singular genus, on ac- 

 * count of the difficulty of placing it properly in the system. By the approxi- 

 mation of the metasternum to the head, and the reception of the middle feet 

 in excavations, it is related to Dorcatoma, but the form of the body, the struc- 

 ture of the antennas and head are those of Anobium. The head, although 

 protected in part by the prolonged metasternum, does not touch it in any 

 position. 



By the epipleurae foveate for the reception of the hiud knees, this genus 

 resembles Theca. 



But one species is known to me. 



[Oct. 



