266 ME. E. m'lachlan's eevisiok of 



" chrysops" in his own handwriting. Unfortunately this collection 

 passed through so many hands before it reached its final resting-place, 

 that too great reliance should not be placed on the labels when the 

 insects do not agree with the descriptions. 

 O. STRiGATUS, p. 233, 2=0. strigatus, Burm. This will not generically 

 agree with Osmylus, as was pointed out by Burmeister. Recently 

 Hagen (' Hemerobiidarum SjTiopsis Synonymica') has briefly diagnosed 

 a new genus for its reception, but without name. I propose that of 

 Porismus, which ma)^ be thus characterized : — 



POEISMTJS, n. g. 

 Antennse moniliformes, alis breviores. Caput parvum, fronte elon- 

 gato-triangulari. Palpi maxillaris articulis iucrassatis. Ocelli 

 tres, approximati. Protliorax elougatus, duplo longior quam 

 latior, antice gradatim angustior. Alee latse, apicibus rotunda- 

 tis : anticse spatio costali basi dilatato, venulis costalibus trans- 

 versalibus perniimerosis ; subcosta ciim radio conj iincta, venulis 

 transversalibus in spatio subcostali numerosis ; sectore prime 

 cseteros emittens, ab radio distaute sed ad apicem approximato ; 

 venis longitudinalibus 5" et 6" parallelis, curvatis ; venulis trans- 

 versalibus pernumerosis. Pedes gi'aciles, hirsuti ; tarsi articulo 

 primo cseteris longiore ; unguiculi simplices ; pulvilli magni. 

 Abdomen gracile. 



It differs from Osmylus, inter alia, by its longer and more slender 

 protliorax, and especially in the neuration. In Osmi/lus the first 

 sector runs parallel with the radius, and is separated from it by a 

 small space, whereas in Porismus it is distant, excepting at the 

 apex ; in Osmyhis there is only one transverse veinlet, placed at 

 the base of the subcostal area; in Porismus there are numerous 

 veinlets, along the whole length of that area ; the direction of the 

 5th and 6th longitudinal veins is also different, and the network 

 generally much closer. 



P. striffattis appears to be very common in Australia, judging 

 from the numerous examples I have seen. 



O. VALiDus, p. 233, 3=Polyst(£chotes punctatus, F. teste Hagen, who 

 states that he has seen the type described by Fabricius in Banks's 

 Museum. I have been unable to find this type. It is singular that 

 Fabricius should, a few yeai-s later, have again described an insect so 

 little variable under another name {Hemerobius nebulosus). 



O. TENUIS, p. 233, 4. For this insect I propose the generic term Ste- 

 ■nosmylus ; the genus should probably be placed between Myiodaclylus 

 and Osmylus ; it possesses the ocelli and antennse of the latter, but the 

 form of the plantulae approaches that of the former; the general form 

 is remarkably narrow. 



