20 NOTES ON CHAIXIDI*:. 



In the ' Entomologist,' No. 88, p. 264 (March, 1871), Mr. Ritsema 

 states that the galls found by Mr. Traill, near Aberdeen, on Ammo- 

 phila arundinacea (Psamma arenaria, L.), were made by Eurytoma 

 longipennis, and that they also occur near Landvoort in Noord-Hol- 

 land, and that the economy of the fly is detailed in the ' Archives 

 Neerlandaises des Sciences exactes,' vol. v. 1870 ; and is also noticed 

 in the ' Nederlandsch Tydschrift voor Entomologie,' 2nd Ser. vol. vi. 

 1871. 



The Eurvtomae and the Decatomae are generally supposed to be 

 parasitic; but it has not yet been ascertained whether their larvae 

 feed on the inhabitants of the galls or on the substance of the galls. 

 Ratzeburg has published in his work, ' Die Ichneumonon,' a very 

 large list of the insects which are the victims of the Hymenopterous 

 parasites, and it will be seen that in many cases one kind is the prey 

 of several parasites, and that one parasite (among others Eurytoma, as 

 is also observed by Dr. Giraud) preys on several kinds. Others seem 

 to be exclusively attached to one victim for the maintenance of their 

 young by means of the insertion of their eggs, and to resort instinct- 

 ively for that purpose to the same kind of object whence they emerged, 

 and to succeed in finding it. It is not yet known whether a parasite, 

 of which several species are victims, has a propensity to resort for 

 oviposition to the same kind of habitation in which it passed its 

 earlier life, or whether it takes the victim that is most convenient to 

 it at once, or when it has failed to find the species whence it 

 emerged ; or, are there hereditary peculiarities in the families of the 

 same species, and does one family live exclusively, generation after 

 generation, in the larvae of beetles, another in the larvae of moths, 

 another in Cynips larva), and another in Dipterous larvae ? 



The species recorded as E. Abrotani in the Brit. Mus. List of 

 Chalcidiae, p. 8, may be identical with E. tibialis, Zett. Boh. Kongl. 

 Vet. Ak. Handb. (1835), 232, and with E. rubicola, Giraud. 



The species of Eurytoma described by Boheman have been all 

 recorded in the above-mentioned list, with the following exceptions, of 

 which the second and, perhaps, the third are species of Isosoma, 

 — E. maura, E. pilicornis, E. brevicornis, E. pubicornis, E. obscura. 



Isosoma flavimana is mentioned inadvertently as a Eurytoma 

 in this list. 



Zetterstedt, in his ' Insecta Lapponica,' describes Eurytoma 

 guttula and E. minuta : the first may be identical with Isosoma 

 verticillata ; aud the second with I. minor. 



Eurytoma atra, Nees, is probably not one of the Eurytomidae. 



Among the species described by Foerster .Eurytoma gracilis, E. 

 scabra, E. pumila, E. petiolata and E. punctulata are Eurytoma?. 

 E. fla_yjp_£s and E. humeralis belong to Isosoma. 



