IOO TRANS. ST. LOUIS ACAD. SCIEN'CE. 



row but as long as the claws. Wings with a large pentagonal 

 areolet, sometimes incomplete by its terminal vein being subobso- 

 lete. When the areolet is complete the bulhe A and B cover 

 nearly the whole of its terminal side and are separated only by a 

 minute dot, C and D are confluent or separated from each other 

 only by an indistinct dot, and E is as close as possible to the angle 

 of the ist recurrent vein. When the areolet is incomplete A and 

 B are absent, the other bulla? remaining the same ; and there are 

 then consequently but 2 bulhe, CD and E, instead of 4, A. B, 

 CD, and E. 



Distinct from Exochus and Polyrhabdus by its hunched scutel, 

 by its long, toothed tarsal claws, and its large pentagonal areolet : 

 and from Alomva by its sessile abdomen, its wings as long as usu- 

 al, and with the terminal veins distinct, its toothed claws, etc. 



[Mr Walsh considered the two following species as belonging to a new 

 genus which he called Pac/iyonyx ; but they cannot be generically separated 

 from Orthocentrus. Grav. — Cresson.] 



[OrthOCeiltrilS] trffaSCiatUS, n. sp.-^$.— Black. Head subopaque with 

 very minute, rather close-set, punctures, more sparse on the subpolished 

 vertex. Face, cheeks, and the whole mouth, white. Antennae § as long 

 as the body c?i \ as long $. with the first joint of the flagellum about i\ 

 times as long as wide, and the following joints about twice as long as 

 wide, brown-black, the scape and the extreme base of the flagellum whitish 

 beneath, especially in d- Thorax polished, with very minute, rather 

 dense punctures, more sparse on the mesothoracic pleura. Metathorax 

 transversely rugose above, with 4 longitudinal subequidistant carina? all 

 attaining the lunate area of the posterior declivity, which is bounded by 

 a well-defined carina throughout. Lower face of the mesosternum rufous, 

 and in d its pleura also fully half way to the wing. Abdomen opaque, 

 very finely and rather densely rugose, subpolished towards its tip and at 

 the tips of the joints. Joint 1 in d full twice as long as wide, in ? \ 

 longer than wide, d? I wider behind than before, d with its sides nearly 

 straight, 0. with its sides strongly convex for the ist £, thence gently con- 

 cave nearly to the tip, so that the whole joint is elongate-campanulate, 

 <d$ geniculate at \ the way to its tip, which is bisinuate, its 2 carina? 

 distinct nearly to its tip and enclosing in their basal i a round excavation. 

 Joint 2 in d longer by \ than wide, d? with a large, impressed, lateral, 

 sub-basal puncture, joint 3 square in d, joint 2 square in $, the rest in 

 d 1 ? gradually shorter. Joints 2 and 3 with their terminal \ clay-yellow, 

 and joint 1 with a similar band, which in $ is narrower, darker and less 

 obvious. Venter d $ yellowish except at tip. Four front legs d $ yellow- 

 ish-white ; hind legs very pale rufous, d with the coxa? brown above and 

 the entire femora, or sometimes only their upper surface, and sometimes 

 the tip of the tibia;, brown. Wings subhyaline; veins brown; stigma 



