BY EDWARD NEWMAN. 415 



femora femiginea : protibics ferrugin(s : mesotihice ferru- 

 ginece, extus macula magna nigra: metatibice nigrce : 

 protarsi ferruginci: mesotarsorum articuU V\ T\ 3""*"". 

 nigri, ferrugineo contaminati ; 4°'. 5"^''"% ferniginei ; meta- 

 tarsorum artictiU V\ T\ 3"'*''"^ nigri; 4"". 5>'"^''\ferrvginei: 

 proalce, metalccque croceo inquinatce, marginibus fvscis. 

 (Long. Corp. 1| unc. ; Alar, dilat. 2 unc.) 



Sirex nigricornis. Fab. Ent. Sysl. Tom. II. p. 126. 



In order to save trouble and avoid repetition, I have given 

 the whole of the generic and specific characters in Latin, and 

 each under a single head. A single specimen of the splendid 

 insect described has been taken in Essex on the blossom of a 

 Dahlia, and transmitted to me by my friend Christy : the 

 colour of the twelfth segment and of the femora, besides three 

 additional joints in the antennas, distinguish it from iS. Juvencus. 



Class. — Neuroptera. 

 Natural Order. — Perlites, ined. 

 Genus. — Isogenus.'' Newman. 



Sexuum amborum alis pariter repandis, pariterque abdominem 

 tegentibus ; telo setis dxiabus instructo. Ea descriptione Perla, 

 Mc e Nemoura distinguebis : mox fusloremconatus. 



Perla . . . Geoffroy Latreille. 

 Phryganea . Linnceus. 



I so. nubecula. Proalce sordidcs hyalince, nubecula costali 

 ultra medium fused. 



Body dark brown ; head and prothorax with a longitudinal ochreous 

 line ; fore-wings hyaline, slightly tinged with brown and having 

 a little oval cloud of a darker brown colour on the costal margin 

 situated about one-third of the distance from the tip towards the 

 body : hind-wings beautifully hyaline, legs pale brown. (Length 

 ^ inch. ; breadth 1^ inch.) 



This insect is abundant in the neighbourhood of running 

 waters in Herefordshire, Worcestershire, Nottinghamshire, &c. 

 and is the favourite food of trout and grayling. 1 cannot find 

 that any author has described or named it. 



* \ffos par, yivos sexus. 



