THE CANADIAN ENTOMOLOGIST. ^51 



SOME NEW NEMATIDS. 



BV C. L. MARLATT, U. S. DEPT. AGRIC, WASHINGTON, D. C. 



The following descriptions of sawflies belonging to the subfamily 

 Nematinse include, with one exception, a number of species which have 

 been reared from the larvae by Mr. H. G. Dyar. Mr. Dyar is anxious to 

 publish the descriptions of the larvae, and the technical descriptions of the 

 species presented herewith are made to enable him to assign his larvae to 

 described species and avoid the difficulties which would arise from the 

 description of larvse before the adult insects have been characterized. 

 The very valuable work which Mr. Dyar is doing in rearing larva; is re- 

 sulting in the clearing up of some puzzles in the classification of insects, 

 and has no more interesting outcome than the fact that many of his 

 rearings, at least in the line of sawflies, prove to be of species hitherto 

 undescribed, showing how little we really know of the insects of this 

 group in this country. The adults of most sawflies rarely leave their 

 food-plants, and live but a few days, and hence it is not at all to be 

 wondered at that so many species occurring on common plants have not 

 been taken by collectors. The collected species, in fact, are usually only 

 those which happen to frequent flowers and those taken by random 

 beating, which, with insects of quick flight, like many sawflies, is not a 

 very successful method of collecting. A vast deal of work will have to 

 be done on the lines followed by Mr. Dyar before anything like an 

 adequate knowledge of our insects in this family will have been gained. 

 These species are additions to the recent revision of the Nematina?, pub- 

 lished by the Department of Agriculture, as Technical Bulletin No. 3 of 

 the Division of Entomology, and are described in conjunction with the 

 tables and descriptions therein contained, so that the affinities of these 

 additional species may be easily recognized. 



Camponiscus americamis, n. sp. 



Female. — Length, 6 mm.; a short, robust species ; head broad, as 

 wide or wider than thorax ; clypeiis deeply circularly emarginate ; lobes 

 broad, rounded ; walls about ocellar basin sharply defined ; frontal ridge 

 strong, bulbous, unbroken ; fovea broad, deep ; antennai short, tapering, 

 smooth ; joints three and four subequal, or three slightly longer 

 than four ; venation normal for genus ; third cubital cell of left wing 

 divided by a cross vein ; claws bifid ; teeth not very long, stout \ sheath 

 obliquely tapering on lower margin, fringed with short hairs ; cerci long, 

 strongly tapering. Colour reddish-yellow ; antennae dark brown above, 



