of the Oil Beetle, Meloé, and of the Strepsiptera. 343 
the whole on each segment are of equal length, so that the appearance of 
the larva under the microscope strongly reminds us of the genus Polyxenus 
among the Myriapoda, or of the larva of Attagenus or Dermestes amongst the 
Coleoptera. The ninth segment of the abdomen, the thirteenth of the whole 
body, is armed with a pair of elongated caudal styles or setze; and the infe- 
rior surface of the fourteenth or anal segment is soft, prehensile, and em- 
ployed by the larva in locomotion, like the anal prolegs in other larvee. The 
caudal styles are distinctly articulated to their segment by a large and a small 
joint, but I have not been able to detect any articulation in the remaining 
portion of these organs with the instrument I have employed, a triplet magni- 
fying about 450 diameters. 
The legs are formed of a cozal joint, a femur, a tibia, and a four-jointed tar- 
sus. The coxa is a large and powerful joint; the posterior one is much larger 
than the others, and the whole are armed, each with four curved stiff spines. 
The femur is also a strong joint, and has two small spines at its distal, or tibial 
articulation. The tibia is elongated, slender, and somewhat clavated at its 
articulation with the tarsus, where it has a short spine on its internal margin. 
The tarsus is long and composed of four joints. The basilar joint is very 
short, but the distal one is large and spatulate. It is in fact a double joint, 
so that the true tarsal joint is the shortest, and the first metatarsal is the long- 
est. The tarsi of the posterior pair of legs are much smaller and shorter than 
those of the first and second pairs. The third and fourth terminal joints are 
not spatulate, but are very narrow, weak and slender. This appears to be a 
character common both to Stylops and Xenos. 
LOCOMOTION OF THE LARVA or STYLOPS. 
When the larva attempts to walk on a smooth surface, as on glass, it moves 
very tardily, and its long tarsi are bent irregularly ; but when attached to the 
hairs or body of a bee, its power of locomotion is much greater. When climb- 
ing up a hair it moves almost precisely like the larva of Meloé, but very much 
more slowly. It first shortens its segments and affixes itself firmly to the hair 
with its anal prolegs, and then, elongating its body, steps onwards, making 
use of its thoracic legs alternately in the act of progression. When left for a 
few hours on some hairs from a bee, on the glass object-plate of a microscope, 
