118 



MR. R. M'LACHLAN ON NEW FORMS, ETC., 



to Lasiocephala, with which it has some affinity iu the maxillary 

 palpi ; but the extraordinary form of the antennae is without 

 parallel anywhere in the Trichoptera. In Nosopus the anterior 

 legs were the members in the construction of which nature had 

 departed from her usual routine ; here the legs present no special 

 characters, but every thing is thrown into the development of the 

 antennae, with a result which, to say the least, is bizarre. The 

 groove or pouch of the anterior wings is not of so great signi- 

 ficance, as modifications of this already exist in many genera, 

 and where such a groove is present, it often, as in the present 

 instance, causes irregularity in the neural arrangement. 



The female will probably be found to have ordinary antennae, 

 and to resemble that of Mormonia. 



Dinarthrum ferox, sp. nov. D. fusco-testaceum. Antennarum 

 articulus basalis fuscus, fimbria grisea, ad apicem flavescente ; articuli 

 caeteri pallide flavi, fusco-cingulati. Palpi flavi, maxillares griseo- 

 hirsuti nigroque squamati. Pedes pallide flavi. Abdomen supra 

 fuscescens, infra ochraceum : appendices inferiores ad apicem longe 

 dentatae. Alae pallide griseae, griseo-fimbriatae, nigroque squamatae : 

 anticae margine costali basin versus sulcoque nigro-fimbriatis (c?). 



Long, antenn. artic. primi 2f lin. ( = 6 mill.); long. corp. 2f lin. ( = 6 

 mill.); exp. alar. 10 lin. (=21 mill.). 



Hab. in India septentrionali (in Mus. auct.). 



Fuscous, or yellowish-fuscous, all the under parts of the thorax yellow. 

 Head fuscous above, yellow beneath, clothed with greyish fuscous 

 hairs : basal joint of antennae fuscous, becoming yellowish towards 

 the apex, the basal portion of the tooth almost black and somewhat 

 shining, fringes dark grey, blackish at the basal portion, and yel- 

 lowish at the apical ; rest of the antennae pale yellow, with brown 

 rings : maxillary palpi yellow, clothed with long dark grey or blackish 

 hairs, intermingled with a few black scales ; labial palpi pale yellow. 

 Legs yellow, with yellow spurs. Abdomen somewhat fuscous above, 

 the margins of the segments broadly darker, under surface ochra- 

 ceous : the margin of the last dorsal segment is produced into a tri- 

 angular prolongation in the middle ; from beneath this prolongation 

 proceeds a yellow, shining, triangular lamina, which is deeply grooved in 

 the centre, the sides sloping obliquely upwards, having the appearance 

 of two valves soldered together ; app. sup. yellow, short and broad, 

 subquadrate, proceeding from beneath each side of the prolongation 

 of the last dorsal segment; app. inf. long, yellow, directed up- 

 wards, the apex furnished with two long spines or teeth, each of 

 which is as long as the simple basal portion,, the appendices are 

 hairy ; interiorly, viewed from beneath, between the app. inf. are 



