J. H. MERRILL 115 



longitudinally throughout its whole length. On the cpisternuni, 

 a short distance behind its front margin, is a nearly vertical 

 suture extending about half way up to the dorsal margin of the 

 plate, crossing it beneath and continuous with the corresponding 

 suture of the other side, separating the lower, anterior portion of 

 each episternum from the remainder. This portion is called the 

 prepectus (Ppct.o). The epimeron (Epm.2) is a narrow band 

 separated from the episternum by a suture extending in a straight 

 line from the hinder base of the fore wing downward and back- 

 ward to the mesocoxa (Cx.2). The sternal area is flat beneath, 

 punctured and sometimes striated. 



The distinguishable plates of the metanotum are the scutum, 

 scutellum and postscutellum. The region here called metanotum 

 is the one which has been usually termed the postscutellum of 

 the mesothorax by the systematists. The metascutum (Sct.2) 

 lies immediately behind the scutellum of the mesothorax. Its 

 narrow dorsal surface is sunken below the surfaces of both the 

 mesoscutellum and the metascutellum. Laterally it consists of 

 two deflexed regions. The hind wings are dorsally attached 

 by a membrane, to the scutum, and behind and below are simi- 

 larly attached by a forward projecting process of the metapleuron. 

 In the anal and humeral angles are borne the small, sub-alar 

 basal wing sclerites. The scutellum (Scl.3) consists of a raised 

 median portion. Immediately posterior to the scutellum lies 

 the postscutellum (Pscl.3) which is a sunken, narrow, transverse 

 bank-like region fusing laterally with the metaepimeron. 



The pleurum consists of an episternal and epimeral region, 

 of which the former is much the larger. That portion of the 

 pleurum which is fused with the metapostscutellum is epimeral 

 (Epm.3). The suture which separates the epimeron from the 

 first abdominal segment becomes lost for most of the distance 

 along the ventral margin of the latter segment, reappearing 

 again for a short distance at its hinder, ventral portion. The 

 main part of the episternum (Eps.3) lies beneath the metae- 

 pimeron and its hinder margin articulates with the metacoxa 

 (Cx.3). The upper, anterior corner is prolonged into a narrow 

 bank-like region lying betwecni the mesoepimeron and the fused 

 metapostscutellum, and metaepimei-on. It is separated from 

 each by sutures. The pleura are fused with the sternum which 



TRANS. AM. ENT. SOC, XLI. 



