222 BRITISH ICHNEUMONS. {Prislomerus 



Tribe 



PRISTOMERIDES. 



This Tribe is instanlly recognised from all oilier Ophioninae by the 

 strong tooth beneatli the hind femora, in fact very few Ichneumonidae 

 have so conspicuous a distinguishing feature, which is shared only by 

 certain Xoridides, treated of in my third volume of the present work. 

 This tribe has hitherto been placed in juxtaposition to the Cremastides, 

 and perhaps a more natural sequence would be found hence through that 

 Tribe to the Campoplegid genus Nevwitis. No one who has studied ex- 

 otic forms, however, can have a doubt of the very close association of the 

 present Tribe with the Anomalides and indeed, in such genera as the neo- 

 tropical EiphosoDia, treated of under the latter in my Revision ot the 

 Ichneumonidae, ii., it is extremely difficult to draw a line of demarcation. 

 Only a single palaearctic genus, with two or three European species, is 

 known.* 



PRISTOMERUS, Curtis. 

 Curt., B.E. xiii, 1836; Pachymcrus, Gr. I.E. iii. (1829), 721 {ncc Thunb.). 



Head transverse and not buccate; eyes in 9 slightly and in J strongly 

 convergent above; ocelli subcontiguous with eyes; clypeus basally dis- 

 creted and apically rounded ; mandibular teeth of equal length. Anten- 

 nae short and not reaching beyond apex of thorax, with the flagellum 



* Genus DEMOPHORUS, Thomson. 

 Thorns. O.E. xiv. 1890, 1457; (?) Dimophora, Fst. Ver. pr. Rheinl 1868, p. 155. 



This interesting genus, whicli Brischke did not describe though he assigned three Prussian 

 species to it, was treated of by Thomson, along with Pristomeriis, at the end of liis paper on Creiiias- 

 tus ; Schmiedel<necht lias placed it actually in the Pristomerides, thougli acknowledging its utter 

 lack of femoral dentitions. I fail to see tlie least relationship between Deiiioplwriis and eilhei of these 

 genera, so remarkable for their large stigma, while here it is of no more that normal size : the posi- 

 tion assigned it by Brischke, between Canidiella and Nemcritis even, is more tenable. A careful 

 examination has convinced me that we liave liere an aberrant Cryptid ; and I am sorry to have 

 omitted tiiis genus from the second volume of Ichn. Brit., for the whole conformation with two ex- 

 ceptions cannot be distinguislied from that of Idiohspa {cf. lib. cit. ii. 296). These two exceptions are 

 found in the neuration and, to a less extent, the metathoracic structure, for the spiracles here are 

 small and circular witli traces— by no means complete areae with strong costae as stated by Schmie- 

 deknecht (O.I. 2013), but somewliat distinct traces — of metanotal areae, such as are often apparent in 

 species of Sptlocryptiis ; the other exception is remarkable for the very short basal radial abscissa and 

 subcircular, subpetiolate areolet with very thick nervures. The points of analogy are entirely 

 obvious and in every other particular Demophorus agrees ad amussim with my description (lac. cit.) of 

 Idiolispa, notably in the wliole abdominal structure, especially the basal segment and defiexed tere- 

 bra, the abruptly declived head and metathorax, elongate hind legs and calcaria. I do not find that 

 the central segments are, as stated by Schm., at all rugose-striate ; they are on the contrary particu- 

 larly nitidulous. 



We have some right to a second species of this genus in Britain, since Stephens (Illus. M. vii. 213) 

 recorded from Darenth Wood Mesoleptus evanialis, Grav. (I.E. ii. 16), wiiich Pfankuch found synony- 

 mous with Dimorpha cogiiaia, Brisch. Schr. Danz. 1880, p. 177) ; but I have no faith in this record. 



I. robustus, Brisch. 



Dimophora robtista, Brisch. Schr. Nat. Ges. Danz. 1880, p. 156, J" ? . Demophorus arenicola, 

 Thoins. O.E. xiv. 1457, J ? . 



Head and thorax finely and closely alutaceo-punctate and somewhat shining, with short pubes- 

 cence ; the former short, scarcely constricted but abruptly declived posteriorly. Antennae of ? not 

 very long, of cf nearly as long as body. Thorax convex, with the discal areae of the short metathorax 

 obsolete but traceable. Scutellum not deplanate, only basally margined. Abdomen black with the 

 second to fourth segments and apex of first broadly red in ? , and the second and third with post- 

 petiole red in cf ; basal segment glabrous; four apical segments of ? subcompressed ; valvulae of 

 i subelongate ; terebra about half length of abdomen, deflexed. Legs red with coxae and trochan- 

 ters black, and hind tarsi piceous. Recurrent nervure emitted before centre of the strong areolet; 

 nervellus subgeniculate below its centre. Length, 5-7 mm. 



Thomson records it from Norway, Sweden and Germany, where Schm. finds it commonly in 

 summer, usually on sunny hill sides. It was consequently to be expected with us, though not 

 hitherto recorded. The late Alfred Beaumont took several specimens, of which he was so good as to 

 give me some, in just such a situation as the above on Box Hill in Surrey on 31st July, 1897. 



