INTRODUCTORY PAPERS ON ICHNEUMONID^. 207 



Pkisticekos, Grav. 

 Scutellum black, sometimes white at the apex ; abdomen black. 

 Ring of antenna), orbits of eyes, and two spots on the metathorax, 



white; legs black. 

 Brischke says the colour of the female is like the male, that the apical 

 margins of 5th to 7th segments are narrowly white, but that the 

 antennae of the female are not serrated (male and female). 



1. serrarius, 5^ — 6 lines. 



This rare species — of which Gravenhorst wrote *' an Euro- 

 pseum," and Wesmael knew only one sijecimen, captured near 

 Diest — is beautifully figured, with an antenna magnified, on 

 Wesmael's plate of the Ich. platyuri (figs. 7, 8). It was regarded 

 by Marshall as only reputed British ; there is, however, a speci- 

 men in the British Museum, from Desvignes' collection, which was 

 taken by the late Fred. Smith in Coombe Wood, in 1839. It is 

 doubtless to this that Wesmael refers when, in the N.B. to the 

 explanation of his plate, he says : " Depuis I'impression de ma 

 notice sur les Ichneumones platyuri (Bull, du 3 Dec. 1853), j'ai 

 re^u une lettre de M. Walker, ou il m'apprend que M. Desvignes 

 a aussi decouvert, aux environs de Londres le Pristiceros serrarius, 

 Grav., ainsi que mon Eurylahus dims, dont il connait meme les 

 deux sexes." Brischke bred a male from Boarmia conso7'taria 

 pupa ; and the female, referred to above, was captured on August 



20th, 1876. 



Platylabus, Wesm. 



Section 1. — Thorax and abdomen blue-black. 



Antennae white-ringed ; front legs pale. 4. nigrocyaneus, 4i lines. 



Section 2. — Abdomen black. 



A. Hind legs black ; antennae white-ringed ; scutellum black (a var. of 



female with pale apex). - - - 2. tenuicornis, 5 lines (s). 



B. Hind femora red. 



a. Antennae of female white-ringed ; apex of scutellum pale, sometimes 



black. Gastrocaeli deeply sunk. 6. pedatoHus, 4 — 5 lines (s, I). 



b. Scutellum and antennae (a var. of female, sometimes with 12th and 



13th joints white above), incision of 2nd segment, or 1st to 3rd, 

 reddish ; a yellow spot at the apex of the cheeks against the 

 mandibles. Gastrocseli almost obsolete. - Thedcnii, 3 lines. 



Section 3. — Abdomen black, all or some of the segments with the apical 

 margins entirely or partly white. Scutellum entirely, or apex, white. 



A. Greater part of femora, especially the hinder ones, black ; antennae 



of female wliite-riuged. - - 3. dolor onus, A^ — 5 lines. 



B. Greater part of femora red, or all red ; antennae white-ringed. 



5. variegatus, Ai — 5 lines. 



