116 rROCEEDIXGS OF THE NATIONAL MUSEUM. voi>. 63. 



I have seen types only of the genus Dolicliotrypes. All synonomy 

 is therefore based on a study of the original description and of iden- 

 tified specimens in my own and in the National Collection. 



Species which belong to Leptacis have been referred to Psilus (by 

 Spinola), to Platygaster (by Haliday, Walker, Curtis, and Taschen- 

 burg), to Ichneumon (by W. Kirby), to Synopeas (by Thomson), to 

 Ceraphron (by Say) , to Piestopleura (by Ashmead) , and to Amhlyaspis 

 (by Ashmead and Brues) . - More exact data on this matter can be 

 obtained by consulting volume five of Dalla Torre's Catalogus 

 Hymenopterorum. In studying our fauna the notes given above 

 will suffice. 



Synopeas is really inseparable from Leptacis although many species 

 can be placed definitely in one genus or the other by the use of 

 Foerster's generic key-^ and the descriptions following it. I have 

 numerous specimens in my OAvn collection showing transition in the 

 structure of the scutellum. Typical Synopeas Foerster has the scutel- 

 lum broad and depressed basally, with a short thorn at tip. Consid- 

 erable difference is found in typical forms of Leptacis Foerster where 

 the scutellum is elongate and produced into a long acute spine pos- 

 teriorly. 



The presence of a low and flat scutellum is the only character used 

 by Foerster to separate Anopedias from related genera {Synopeas, 

 Leptacis, etc.). Variation in scutellar structure seems to be of no 

 generic value throughout the entire subfamily. Leptacis striatifrons 

 Ashmead, undoubtedly a true Leptacis species, runs to Anopedias in 

 Foerster's generic key.^^ 



Ectadius of Foerster includes forms which, except in the elongation 

 of the abdomen in the female sex, are typical of Synopeas Foerster. 

 Dolicliotrypes runs to Ectadius in Foerster's generic key^* and agrees 

 with Foerster's description on page 113. , 



Species should agree in every particular Math the following diagnosis 

 before they are assigned to the genus Leptacis: 



Head transverse; lateral ocelli nearer the eye margin than to the 

 anterior ocellus; antennae 10- jointed in both sexes, in the female 

 with a more or less distinct 4-jointed club; in the male the antennae 

 may be covered vnth long or short erect hairs, and may have the 

 fourth joint excavated basally, or swollen medially without any 

 excavation, or cylindrical; mandibles bidentate, the teeth equal; 

 thorax usually more or less compressed, frequently elongate; notauli 

 incomplete or complete; scutellum usually -svith a spine or tubercle 

 at apex, flat or convex, either wide or narrow at the base; wings 

 veinless, pubescent, ciliate at the margins: abdomen in both sexes 

 convex above and below, not flattened as in Platygaster; abdomen 



8' Hym. Stud., Heft. 2, 1S56. p. 108. "Idem. "Idem., p. 107. 



