178 THE ENTOMOLOGIST. 



Ophion, Fabr. 



Almost entirely testaceous. 



A. Thorax black-marked (male and female). 



a. Base and apex of abdomen black ; sutures of thorax black. 



5. marginatum, 7 — 10 lines. 



b. Extreme base of abdomen not black ; back and apex of abdomen more 



or less black. 



* Antennae red. .... 4. ventricosus, 4|— 1\ lines. 

 ** Antennae black at the base. - - 6. bombycivorus, 9 — 10 lines. 



B. Thorax not black-marked (male and female). 



a. Radial nervure of front wing wavy. - 3. undulatus, 9 — 14 lines. 



b. Radial nervure straight. 



* Lines on thorax and scutellum yellow. 



f External and internal nervures of praediscoidal cell (pi. i., figs. 2, 10) 



of equal length. .... minutus, 4£ — 5? lines. 



ff External nervure of praediscoidal cell one-third shorter than internal 



nervure. 1. obscurus, 4 — 10 lines. 



** Marks on thorax sometimes pale, not yellow. - 2. luteus, 4 — 9 lines. 



This well-marked genus is the type of the family, and 

 contains two or three of our best-known Ichneumons, which are 

 generally common from early spring to late autumn. Their 

 habit of coming to light has already been noticed. The neuration 

 is remarkable, hut it is very inconstant in its minor details in the 

 same species : the upwards of 60 -jointed antennae is note- 

 worthy (in O. undulatus the male has 66, the female 63 ; 

 O. merdarius, male, has 68 ; and O. ramidulus, male, 70) ; 

 and Curtis remarks on the difficulty of separating the sexes, 

 and notes that frequently only one sex of Ophion (as in 

 many other genera) " is bred from an infested larva, although a 

 considerable number may be hatched." O. minutus, Kriechb., is 

 added to the six species included as British in Marshall's cata- 

 logue (see Entom. xiii. 54, and Trans. Ent. Soc. Lond., 1881, 

 p. 157). It is not uncommon, and doubtless was formerly over- 

 looked as a small variety of the common O. obscurus. Vollenhoven 

 gives beautifully coloured figures of O. obscurus, minutus, luteus, 

 undulatus, and ventricosus on plates 28 and 39 of ' Pinaco- 

 graphia ; ' and Jurine gives a fair coloured figure of O. marginatus 

 in his ' Nouvelle Methode,' pi. 8, fig. 4. O. ventricosus is figured 

 on Curtis's plate, 600. In addition to Gravenhorst and Holm- 

 gren, reference should be made to Taschenberg's " Zur Kenntniss 

 der Gattung Ophion Fab." (Zeits. Ges. Nat., vol. xlvi., pp. 421 — 

 438). The species are all parasitic on Macro -Lepidoptera, and 



