no 



THE ENTOMOLOGIST. 



the leaf by means of a very delicate, extremely short stalk, 

 and is not visible from the upper side. In shape it is either 



spherical, oval, reniform, or tuber- 

 ris. AC. culate, and has a central diameter 



of two millimetres. In colour it is 

 at first gieen ; but later on it gene- 

 rally changes to a brilliant red. 

 The gall exhibits in section a suc- 

 culent parenchyma; and in the 

 interior is a laiva-cell, without an 

 inner gall. In the month of Octo- 

 ber the galls begin to fall off the 

 leaves : they pass the winter on the 

 ground. Ur. Giraud states that he 

 did not obtain the flies till the fol- 

 lowing summer. — G. L. Mayr. 

 BioRHizA EEKUM. Havlug dcscribed the root, bark, 



and bud-galls, we now come to 

 the large class of leaf-galls, thirty-three of which are 

 described by Dr. Mayr. In his description of this gall he 

 says, as above, that there is no inner gall ; this he subse- 

 quently corrects by saying, "I find a thin, but indistinct 

 inner gall." This species has been recorded from several 

 localities in England and Scotland, and I have found it 

 widely distributed in Essex, but it only occurs on the leaves 

 for about the first fortnight in October, and, like the oak- 

 spangles, it swells up in the winter; so, in order to be 

 successful in breeding the gall-flies, it is necessary to keep it 

 moderately moist. Dr. Giraud, who was the first to breed 

 the Cynips, says : — " It is remarkable that the galls inhabited 

 by the Biorhiza assume a blackish colour and a regularly 

 oval form, w'hilst those which are occupied by other insects 

 remain yellow or red, and preserve their irregular form." 

 Synergus varius, //., and S. Thaumacera,Z)a/w. (= Klugii, H.^ 

 and luteus, //.), are inquilines of this species, both occurring 

 in April of the second year. Dr. Giraud mentions S. vul- 

 garis, H.; but, as this is not confirmed by Mayr, it is 

 probable the specimens were referable to S, varius. 

 Schlechtendal bred a male Callimome from these galls, but 

 the species was not specified. The only other parasite I can 

 find recorded is Mesopolobus fasciiventris, IVesliv., in addi- 

 tion to the Anthomyia (Diplera), which was bred by Hartig, 



