188 Eev. T. A. Marshall's monograph of 



Abdomen not longer than the head and thorax, subsessile. Terebra 

 exserted. 



Head very large, transverse, broader than the thorax; face 

 convex ; clypeus angulated in front, imperfectly discrete, with 2 

 indistinct basal foveae ; eyes small ; cheeks somewhat dilated ; 

 antennae inserted in a large shallow depression of the front ; 

 between them is a compressed dentiform elevation ; those of the ^ 

 as long as the body, of the J hardly longer than the head and 

 thorax. Mesopleurae punctulate, shining, with a crenate furrow. 

 Metathorax depressed, vertical behind. Second cubital areolet, 

 when measured along the cubital nervure, twice as wide as when 

 measured on the radial ; its inner angle incomplete. Legs short, 

 stout ; hind femora edentate. First abdominal segment sub- 

 triangular, striated, the rest smooth ; 2d and 3d segments of equal 

 length ; suturiform articulation visible. 



The genus Cenocoelius was established by Haliday 

 from a British insect which he n?bm.ed flavifrons but did 

 not describe ; he left, however, a sketch of the wings, 

 reproduced in Van Vollenhoven's ' Schetsen.' Certain 

 exotic insects were recognised by F. Smith and Professor 

 Westwood as nearly allied, and the name Cenocoelius 

 was applied to them, while the British type of the genus 

 remained unknown, or received new names from authors 

 whenever it occurred. The first description of Haliday's 

 insect is that by Nees v. Esenbeck, who placed it in the 

 genus Bracon ; in Katzeburg's work it figures as an 

 Opius, and is accompanied by a second congener ; 

 Forster created for them his genus Laccophrys, sub- 

 sequently adopted by Eeinhard, Van Vollenhoven, and 

 others. The second species mentioned by Eatzeburg 

 was known long ago to Linne, and is ticketed in the 

 Linnean collection as Idineumon agricolator and secalis. 

 As there can be no doubt that the insect now to be 

 described is Haliday's type of Cenocoelius, I have 

 restored the proper generic name, leaving the exotic 

 forms to whatever fate may be in store for them ; one or 

 other of the names Capitonim or Aulacodiis may perhaps 

 be conveniently applied to them, and their difi'erences 

 from the British Cenocoelius may be hereafter settled. 

 There seems to be a natural group of some extent to 

 which these insects belong ; some are Asiatic and others 

 American ; they are sufiiciently difi'erent from Helcon, 

 and no doubt require generic division, though agreeing 

 in the mode in which the abdomen is articulated to the 



