190 Rev. T. A. Marshall's monograph of 



The second known species, C. ruhriceps, Ratz., is likely 

 also to be found in England. It differs in being rather 

 larger ; antennae 31 — 34-jointed ; head of the ? rufous, 

 with a black stemmaticum. Several times reared from 

 MagdaUnus violaceus, L., on pine-trees. This is the true 



^ - agricolator 



Ichneumon ,. — 



secaiis 



as labelled in the Linnean collection, and not the 

 Perilitus secaiis, Hal. ; see Trans. Ent. Soc. Lond., 1887, 

 p. 79. The meaning of the double name is hard to 

 understand ; perhaps agricolator and secaiis were after- 

 wards found by Linne to be the same, for in Turton's 

 translation of the * Systema Naturae ' agricolator is 

 thus mentioned : — "Black; head ferruginous ; abdomen 

 sessile. Inhabits Europe. Probably a variety of 

 Ichneumon secaiis.'" The habitat of secaiis, in the 12th 

 ed. of the ' Systema Naturae,' is said to be " in larvis 

 spicarum," in larvae found on ears of corn, which is not 

 unlikely, although different from the origin assigned to 

 Eatzeburg's insect. 



XXI. MACEOCENTRIDES. 

 Form elongate, slender. Head very transverse ; front not or 

 hardly excavated ; foremost ocellus not placed in a fovea ; antennaa 

 elongate ; maxiUary palpi 6-, labial 4-jointed. Mesothoracio 

 sutures distinct. Metathorax deplanate. Fore wings with 3 

 cubital areolets, the 1st separated from tlie prtediscoidal ; radial 

 areolet elongate, cultrate ; metacarpus longer than the stigma. 

 Abdomen longer than the thorax, sessile, linear, or subsessile, and 

 then attenuated at the base ; the segments discrete ; tubercles 

 basal. Legs elongate, slender ; hind femora not incrassated ; 

 spurs of the posterior tibiae elongate. Terebra elongate. 



The first attempt to discriminate these insects from 

 Bracon is due to Curtis, who in 1832 proposed the genus 

 Zele (but in such terms as partially to include Meteorus, 

 Hal.), and in the following year Macrocentrus. Nees v. 

 Esenbeck, in 1834, included the same insects in the 

 1st section of his genus Rhogas (Mon., i., 200). Wesmael, 

 in 1835, again separated the 2 forms united by Nees, 

 giving to one of them (Zele) the name Phijlax, which is 

 preoccupied in Coleoptera ; and to the other {Macro- 

 centrus) the name Rhogas, in a limited sense, the genuine 

 Ehogades being called by him Aleiodes. The two forms 



