of the Oil Beetle, Meloé. 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 Nomade than in those 
from the Andrenide. Both also differ slightly from specimens which I have 
reared from the eggs of Meloé cicatricosus and Meloé 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 setze of the præ- 
anal segment. In all other respects of structure, the specimens found on 
Nomade 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 Meloé. They occur of two 
sizes on the Nomade, 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 sligbt increase in size in speci- 
mens bred by myself from the eggs of /Meloé cicatricosus. 
Baron Walckenaer*, who doubted that the parasites found on Hymenoptera 
are the young of Meloé, obtained a yellow-coloured specimen from Halictus 
Elephas, which differed from all others hitherto described in having the caudal 
setze 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 Dufour} on Andrena was 
similar to Mr. Kirby's species is not certain. From the statement that it was 
furnished with one pair of caudal setz, there is reason to believe that it was 
different. The second pair of setze 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 setze are exceedingly short and slender. Whether the 
black-coloured larvie are in reality the young of any species of Meloe, or 
* Mémoires pour servir à l'Histoire naturelle des Abeilles solitaires qui composent le genre Halicte 
1817, 8vo, pp. 85, 86. t Ann. des Sci. Nat. 1898. ; 
2042 
