of the Oil Beetle, Meloe. 325 



represents the true tarsus, and the lateral elongated tarsal spines, the whole 

 being equally strong, very acute, and spear-shaped. But they differ in the 

 head being more produced anteriorly, and in the prothorax being more elon- 

 gated and quadrangular in the specimens from the Nomadce than in those 

 from the Andrenidce. Both also differ slightly from specimens which I have 

 reared from the eggs of Meloe cicatricosus and Meloe violaceus. In the latter 

 species the head is almost semicircular, the prothorax is rounded behind, 

 broader than long, and much wider than the meso- and meta-thoracic seg- 

 ments ; while the abdominal segments are more pubescent, and have each a 

 pair of short hairs at the sides, corresponding to the caudal setae of the prse- 

 anal segment. In all other respects of structure, the specimens found on 

 Nomadce are similar to those bred from the eggs of M. violaceus, so that they 

 may fairly be regarded as the young of a species of Meloe. They occur of two 

 sizes on the Nomadce, but these are identical in structure. This leads me to 

 the conclusion, in opposition to the opinion often advanced by others, that the 

 larvae grow slightly while on the bodies of the bees, before they are conveyed 

 to the nests. Most certainly I have noticed a slight increase in size in speci- 

 mens bred by myself from the eggs of Meloe cicatricosus. 



Baron Walckenaer*, who doubted that the parasites found on Hymenoptera 

 are the young of Meloe, obtained a yellow-coloured specimen from Halictus 

 Elephas, which differed from all others hitherto described in having the caudal 

 setae only of a black colour, with the exterior pair instead of the interior the 

 longest. These characters convince me that this was a distinct species, although 

 that learned naturalist regarded it only as a variety of the species already 

 described. Whether the specimen found by Leon Dufourf on Andrena was 

 similar to Mr. Kirby's species is not certain. From the statement that it was 

 furnished with one pair of caudal setae, there is reason to believe that it was 

 different. The second pair of setae might perhaps, however, have been over- 

 looked, as in those found by Mr. Smith, which are identical with Mr. Kirby's, 

 the exterior pair of setae are exceedingly short and slender. Whether the 

 black-coloured larvae are in reality the young of any species of Meloe, or 



* Memoires pour servir k I'Histoire naturelle des Abeilles solitaires qui composent le genre Halicte, 

 1817, 8vo, pp. 85, 86. t Ann. des Sci. Nat. 1828. 



2 u 2 



