COLEOPTEUA. 289 



i 



OXYGNATHUS, Dej. 



The Oxygnathi, as to their antennae and palpi, are essentially 

 similar to the preceding Insects, but having, as well as the two fol- 

 lowing subgenera, long, narrow, edentated mandibles which cross 

 each other in the manner of a forceps. Their body is narrow, elon- 

 gated and cylindrical; their antennae shorter than the head and man- 

 dibles united; the labrum rather indistinct, and the thorax almost 

 square. 



The type of this subgenus Scarites elongatus, Wiedem.; 

 Oxygnathus elongatus, Dej. Spec. II, p. 474 is from the East 

 Indies. 

 There, the four exterior palpi, or at least those of the labrum, 

 terminate by a fusiform joint ending in a point. The body is elon- 

 gated and cylindrical, and the mandibles are long, narrow, and 

 without any remarkable teeth, like those of the Oxygnathi. 



Oxystomus, Lat. 



The labial palpi almost as long as the exterior ones of the maxillae, 

 recurved, the first joint salient and cylindrical, the second but slightly 

 elongated, and the last fusiform, long and acutely pointed at the 

 end; the antennae completely moniliform from the middle of their 

 length, with the first joint as long as the three following ones 

 united(l). 



Camptodontus, Dej. 



The labial palpi evidently shorter than the external ones of the 

 maxillae, not recurved, and terminated as well as the latter by a fusi- 

 form joint; a greater part of the joints of the antennae resembling 

 inverted cones; the length of the first hardly surpassing that of the 

 two following ones taken together(2). 



The others, whose anterior tibiae are not dentated externally, but 

 simply didactyle at the end, have short mandibles, projecting but 

 little beyond the labrum; the labrum coriaceous and entire; the li- 

 gula advancing beyond the emargination of the mentum, glabrous, 

 or but slightly pilose, with separate, salient, and membranous para- 



a certain difference of aspect would seem to warrant the supposition that the latter 

 is a distinct species- Although, after the most careful comparison of the two, I 

 confess my inability to point out any truly specific difference, I am still inclined 

 to believe they are distinct. Am. Ed. 



(1) Oxystomus cylindricus, Dej. Spec. I, p. 410. Brazil. 



(2) Camptodontus cayennensis, lb., II, p. 477. 



Vol. III. 2 M 



