1907.] 141 



also showed the larva and pupa of a Diptcron of the genus Microdon, taken in a 

 nest of Formica fu sea at Porlock last month. Mr. R. Shelford, a specimen of the 

 curious parasitic Ortliopterous insect Ilemimerus taljioides, Walk., from Portuguese 

 Guinea; and read a note on "A Case of IIonieDotic Variation in a Cockroach." — 

 H. Rowland-Bkown, Jlon. Sec 



HELP-NOTES TOWARDS THE DETERMINATION OF BRITISH 

 TENTHREDINID2E, &c. (19). 



HT THE UEV. F. D MOHICK, M.A., F.E.S. 



BLENNOCAMPIDES {confinued)^PERICLISTA to BLENNOGAMPA. 



Ill two more genera of the Blennocampides, as in those with 

 which we have just been dealing {Jlhadinocera;a, &e.) the eyes are 

 noticeably remote from the mandibles (" gena? distiiicta^ "). These 

 are PericJista, Kuw., and Ardls, Knw., and of each we have (I believe) 

 two British species 



Periclista, Konow. 



The J c? of this genus are unmistakeable, being the only Blenno- 

 campiils with " continuous external neuration " (Ent. Mo. Mag., 

 March, 1903, p. 53). The $ ? do not possess this character, but 

 they have another vtry distinctive one in tlic outline of the saw- 

 sheath, viewed laterally, with its short but sharp triangular apex 

 (Fig. 11, infra), and one of the two species can be recognised at 

 once by its coloration. 



Our two species are vwlanocephala, F., and lincolata, Kl. I do 

 not remember to have personally met with the latter as a British 

 insect; but it is no doubt Mr. C'amerou's lineolala (recorded from 

 Worcester and Scotland), though it is strange that in giving the 

 characters of the c? lie says nothing about its peculiar neuration. 



Melanoceplialn has the abdomen reddish in both sexes, in lineolata 

 it is black. Melonocephala differs from all our other Bhnnocampides 

 in having both the thorax and the ahdomen mostly red above. lu all 

 other cases either both or one of them is black. Mehinocephala ^ 

 follows the general rule, its red coloration being confined to the 

 abdomen. 



Both in tnelanoccphala and in lineolata the body is a little longer 

 and considerably broader than in Pareophora. 1 make its measure- 

 meuts average about 6 mill. X 2 mill, (in dried specimeus). 



