CONTRIBUTIONS TO OUR KNOWLEDGK OF THE BRITISH BRACONID^. 179 



females but only one male. The species hiis precisely the same 

 habits as Rhogas, undergoing its metamorphosis within the 

 indurated skin of the host. 



Genus 5. — Clinocentrus, Hal.* 



A small genus of moderate sized but little-known insects, 

 distinguished from neighbouring genera by the obsolete suturi- 

 form articulation and exserted terebra of the female. Apparently 

 scarce in some parts of the country, otherwise so jirdent a 

 collector as Bignell would certainly have obtained them in De\on, 

 yet so far as we know he found none. During my several years 

 in the New Forest not a single specimen occurred to me, though 

 Dr. Sharp and Morley have each taken an example in that 

 locality. After my experience in the Forest I was somewhat 

 surprised to find in 1917 one species in very considerable 

 numbers and others more sparingly on the Gog Magog Hills near 

 Caml)ridge. 



Our knowledge of the life-history of these insects is very 

 scanty. Von VoUenhoven tells us that several C. excubitor v/ere 

 reared from pupce of Noctua dintrapezium, and Elisha bred C. 

 exsertor from Hedya neglectana as recorded by Marshall, but 

 unfortunately no particulars are given as to whether the insect 

 emerged from the hardened skin of its host or not. The genus 

 certainly differs rather widely from the other lihogadidce, so 

 much so that Ashmead removed it from the tribe and included 

 it in his Rhyssalini\ , while Thomson placed it with the Exo- 

 thecides. A better knowledge of the habits of these insects 

 might do much to decide the true position of the genus. 



Exsertor, Nees.l 



Probably the commonest species we have. I found it fairly 

 abundantly in a lane on the Gog Magog Hills, Cambridge, in 

 July, 1917, though in 1918, careful collecting in the same locality 

 and at precisely the same time of the year failed to yield a single 

 specimen. I have also obtained it at Chesterton Feu (August 

 1st, 1918) and the Fleam Dyke (August 11th, 1918), both near 

 Cambridge. 



Marshall gives the antennae as 31-36-jointed, though I have 

 seen none with less than 83 or more than 35 joints. In a few of 

 my specimens the third abdominal segment has a rufous tinge ; 

 in the great majority, however, the upper surface of both thorax 

 and abdomen is entirely black ; in all the hind coxfe are more or 

 less infuscated above. The terebra is rather more than two- 

 thirds as long as the abdomen ; this agrees with Marshall, but 

 Nees, in the original description, says — " Terebra longitudine 

 dimidii abdominis." 



* ' Ent. Mag.,' i, p. 260 (1833), iv, p. 94. 



t 'Classification of Ichneumon Flies," p. 142. 



* 'Mon.,' i, p. 207. 



