some British Guiana Hymenoptera. 317 



Subfamily TRYPOXYLINAE. 

 Genus Trypoxylon, Latr. 



T. palliditarse, Saiiss. A fairly common species on the 

 coast lands. 



T. fvgax, F. This insect has been bred from the disused 

 cells of Eumenes canaliculota, 01. It is of fairly common 

 occurrence. 



T. hrevicarinatmn, Cameron. A common and widely 

 distributed species all over the Colony. It usually con- 

 structs its nest of mud cells beneath a palm leaf. Some- 

 times as many as twenty-five cylindrical cells are found 

 cemented together. The largest cells are nearly an inch 

 in length and about \ of an inch in diameter. Small 

 spiders are stored up by this species. 



T. albitarse, F. Bred from a large-sized rounded mud 

 nest. Potaro River. 



T. nitidum, Sm. Issororo, N.W.D. 



T. cineremn, Cameron. The habits of this species have 

 been observed by Mr. C. B. Williams. " An elongate mud 

 cell was constructed by one of these wasps in the angle 

 of the woodwork of a door. WTien making these nests a 

 ' ball ' of mud is collected and ap])lied to the side of the 

 nest, gradually drawing it downwards as it adheres. A 

 shrill buzzing sound is emitted the whole time. Thirty 

 seconds to one minute are occupied in applying one ' ball ' 

 of mud. Spiders are stored." 



Family TRIGONALIDAE 



Genus Trigonalys, Westw. 



T. melanoleuca, Westwood. A number of these insects 

 emerged from the pupae of the Noctuid moth Amyna octo, 

 Guen., which had been taken from just beneath the surface 

 of the soil on a sugar estate. 



Family CHRYSIDIDAE 



Subfamily CHRY8ID1NAE. 

 Genus Chrysis, L. 



C. punctatissima, Spin. A common species on the coast 

 lands. 



C. distinclissima, Dahlb. Bartica, Essequebo River. 

 C parvula, F, East Coast, Demerara. 



TRANS. ENT. SOC. LOND. 1917. — PARTS II, III, IV. (mAY '18) Y 



