February, 18G7,] 193 
DESCRIPTION OF A NEW GENUS AND SPECIES OF BRITISK 
HYMENOPTERA, ALLIED TO PEZOMACHUS. 
BY THE BEV. T. A. MARSHALL, M.A. 
The characters of this interesting insect exclude it from every one 
of the eight genera into which Forster has divided the group. It comes 
nearest to Aptesis, but its rehations will be best understood if we re- 
produce Forster's synopsis, with the necessary addition. See Forster, 
Monogr. der Gattuug Fezomachus, p. 22. 
A. Terebra concealed, or scarcely exserted. 
{^Pterocormiis, Oremnodes.) 
B. Terebra considerably exserted. 
b. Metathorax completely and regularly areated. 
(Stibeutes.) 
hh. Metathorax not areated, or with few and im- 
perfect areas. 
c. Scutellum distinct. 
d. Penult, joint of the tarsi bilobed. 
{Agrothereutes.') 
- Oresbiut castaneus, 
dd. Penult, jomt of the tarsi not bilobed. Marsh. 
e. Eudimentary wings reaching beyond the base of the meta- 
thorax. First segment of the abdomen punctulate, not 
longitudinally rugoee. 
f. Antenna? 2-3 coloured. {Aptesis.) 
ff. Antennae unicolorous. {Oresbius, uov. genus.) 
ee. Eudimentary wings not reaching the base of the meta- 
thorax. First segment of the abdomen longitudinally 
rugose. (Theroscopus.) 
cc. Scutellum obsolete, at least in the ? . {Pezolochm, Fezo- 
machus.) 
Oresbius, n. gen. 
Antennse crassse, capite cum thorace duplo longiores, non convoluta?, 
unicolores. Scutellum conspicuum. Alae metathoracis basin exce- 
dentes; area radialis brevis, ovata ; cubitales 2, cum disci cellulis 
confusse. Areola nulla. Nervi omnes crassi, pilosi. Metathorax 
rugosus, inter rugas punctulatus, non areatus ; pars declivis utrinque 
carina leviter designatus. Segmentum primum triangulare, tuberculis 
lateralibus nullis, basi latissimum, apicem versus gradatim angustatum. 
Abdomen capite cum thorace multo longius, supra depressum. Terebra 
exserta, segmenti primi longitudine. Corpus totum depressum, et sub 
saxis degenti idoneum. 
