﻿102 THE ENTOMOLOGIST , 



leaf, rendered it an extremely difficult matter to determine with 

 any certainty. The larva is a stout yellowish-white grub, re- 

 sembling those of other bees in general appearance. In all the 

 cells opened the larvae were found resting on their backs in a 

 curved position, with the extremities raised and the head in the 

 direction of the entrance to burrow. Four of the larger cells 

 were removed and placed in a glass-top box on October 10th, 

 a portion being cut away from the side of each to expose the 

 larvsB within. The cells being loose in the box often rolled 

 about on its being moved, thus causing them to take up 

 different positions, but whatever position the cell rested in the 

 larva would always assume the above-mentioned position within 

 a short time. From these observations I presume this is the 

 position most favourable for its development. 



The largest larva measured in normal curved position 10 mm., 

 extended 15 mm., and 6 mm. across its widest part. The 

 dimensions of the smallest were : length in curved position 

 7 mm., width 4 mm. 



By observing the larvas as above described, I had hopes of 

 being able to throw some light on the method of the imagines' 

 emergence ; but owing no doubt to the artificial conditions under 

 which it was necessary to keep them, and the difficulty of 

 regulating the supply of moisture, they unfortunately perished 

 about Christmas. Two of these larvae became infested with 

 numbers of pale grey Acari. 



HOPLOTHRIPS CORTICIS: A PEOBLEM IN 

 NOMENCLATUKE. 



By J. Douglas Hood, M.A. 



(Of the United States Biological Survey, Washington.) 



In their ' Histoire Naturelle des Insectes, Hemipteres,' Paris, 

 1843, Amyot and Serville divide the Tubuliferous Thysanoptera 

 into three genera, Hoplotkrips, Haplothrips, and Phloeothrips, the 

 first two being described as new. For the purposes of this 

 paper we are interested only in these two genera, in the inter- 

 pretation of which there is some disagreement. 



Hoplothrips is described as having the sides of the head 

 parallel and the anterior femora armed with one tooth on the 

 inner surface, and to it are assigned four species — H. aculeata, 

 Fabricius, H. corticis, De Geer, H. ftavipes, Haliday, and H. 

 statices, Haliday. Haplothrips is said to differ from Hoplothrips 

 in that the fore legs are not dentate ; and in it is placed only 

 one species, H. albipennis, Burmeister. 



In deciding the validity and application of these generic 

 names, it is first necessary to select the type-species of each 



