414 Sir S. S. Saunders on Hymenopterous Insects. 
Antenna3 prope os insertfe. 
Tibiarum posticarum apex non acuminatus. 
Metatarsi graciles. 
Halticella Osmicida, n. s. 
Fern. Nigra ; abdominis segmentibus lo, 2o, 3o, 4o- 
que (hoc margine excluso), femoribusque posticis, rnfis. 
Caput transversum, densissime punctatum, thoracis 
latitudiue ; oculi magni, distantes, prominuh ; antennje 
nigra3, 10-articulatje, thoracis fere lougitudine, articulo 
basali elongato, depresso, secundo brevi, rehquis subrequa- 
libus; thorax crasse punctatus, pilis albidis compressis 
instructus ; abdomen conicum, articuhs quatuor basaUbus 
lucentibus rufis, quarto margine obscuro, reliquis nigris, 
piHs albidis compressis instructis; terebra brevi, nigra; 
alfB fumata3, basi pehucidfe, venis fuliginosis ; pedes ob- 
scvu'i, tibiis nigro-albescentibus, femoribus posticis valde 
incrassatis, postice subemarginatis, unidentatis, rufis. 
Long. Corp. (cum terebra) 10 mill.; exp. alar. 12 mill. 
Mas, penitus niger, abdomine nitente, alis minus ob- 
scuris, basi pellucidis. 
Long. Corp. 8 mill. ; exp. alar. 12 mill. 
Hob. — Epirus, in rubis exsiccatis. 
This parasite feeds on the adult larvae of Osmia triden- 
tata within their closed pupa-cases, the said larvjB becom- 
ing reduced thereby to an empty desiccated blackened 
shell of the same shape and dimensions as before, within 
which these HalticellcB, each occupying the interior of a 
single larva, undergo their metamorphoses, having the 
head directed towards the broad anal segments of the 
larvas, thus pointing downwards in the briar cells, and 
issuing therefi-om in the imago state about the middle of 
June. 
Larva : milk-white, slightly recurved, gradually taper- 
ing towards each end, the anal extremity smaller than 
head ; divisions of segments strongly arched and deeply 
incised, ha\4ng large intermediate dorsal folds, so that for 
each ventral and lateral division there appear to be two 
dorsal folds, gradually sloping off on each side. 
Length 10—11 mill. ; breadth 3—4 mill. 
