1881. 
271 
fourth segment (the first abdominal) black ; the fifth yellow ; the sixth yellow, mar- 
gined with black, with an irregular black band running transversely across it, and 
extending on the under-surface so as to form almost a complete ring round the body ; 
seventh segment black. There is also a lateral black line along the first two segments. 
The antenna) are twice the length of the head ; the first and second joints yellowish, 
the third and fourth purplish, the articulations of the second and third are black. 
The legs are white, with black articulations. The spring white. 
This insect is undoubtedly near I), muscorum , Nic., but is 
distinguished by the shorter antennae, the black articulations of the 
antennae and limbs, and the greater preponderance of black over the 
whole body. 
The markings in the whole genus Derjeeria are fundamentally the 
same, at least, in the yellow species, the great difference being caused 
by the variability in breadth of the black bands which margin the 
body-segments ; this species has broader black bands than any other 
with which I am acquainted, which give it the appearance of 
being regularly banded with alternate black and yellow. The amount 
of black also varies in this species, apparently according to age ; for, 
in a smaller and presumably younger specimen, the fifth segment is 
yellow margined with black, while in the adults, the black has extended 
entirely over the segment, leaving only a trace of the yellow, and in 
the younger specimen again, the articulations of the feet and the an- 
tenna? are rather grey than black. It is certainly the prettiest species 
that I have as yet seen. 
20, Portsea Place, Connaught Square : 
April, 1881. 
ON PARTHENOGENESIS IN THE TEN TILE EE IN IE TE . 
BY P. CAMEBON. 
Mv observations last year have enabled me to add two species to 
the list of parthenogenetic Tenthredinidw ; and to prove the occurrence 
of complete parthenogenesis in Poecilosoma. pulveratum and Eriocampa 
ovcita. 
A virgin ? of Nematus pavidus, Lep., laid a few eggs from which 
I obtained two males. 
A specimen of Taxonus glabratus , Fall, (agilis, Kl.), bred from 
larva? which fed up at the end of July, laid eight eggs, which were 
certainly fertile, but the larva? perished in the eggs, owing to the food- 
plant drying up. 
Five Poecilosoma pulveratum laid in June from five to eleven eggs 
each, but out of that number only two larvae became full-fed. On 
