18 Bulletin American Museum of Natural History. [Vol. XXIII, 



of the little Chalcidids in a single nest. A careful search will probably show 

 that they are even more abundant. 



In the literature I find the following scattered references to Chalcidid 

 ant-parasites : 



Fritz Mtiller, according to Sharp/ mentions a South American Chalcidid 

 which attacks the larvse of Azteca instahilis in its nests in the Cecropia trees. 

 When the parasite pupates it suspends itself, by its posterior end, from the 

 walls of the chambers like a butterfly chrysalis. 



Wasmann^ cites an observation of Bravms who found a Chalcidid in one 

 of the nests of a South African subspecies of Pheidole megacephala. When 

 the nests were disturbed the workers were seen to carry the parasites, which 

 probably devour the brood, to a place of safety. 



A larva found by Rupertsberger attached to a large Myrmica larva, and 

 mentioned by Wasmann in his ' Verzeichniss ' (/. c, p. 169) as possibly an 

 Ichneumonid, was probably a Chalcidid. 



Perhaps no single group of parasitic insects has greater surprises in store 

 for the future investigator of habits and development than the Chalcididse. 

 This is indicated not only by the fragmentary materials collated in the pre- 

 ceding paragraphs, but more especially by the splendid researches of Bugnon,* 

 Marchal,^ and Silvestri,^ on the extraordinary polyembryony of the Encyr- 

 tinse. These and future researches in the same direction may be expected to 

 bring about many radical changes in the present taxonomy of the enormous 

 family Chalcididse. 



2. The Parasitism of Mermis in Ants. 



Five years ago (June 3, 1901), I found at New Braunfels, Texas, on a 

 shady hill that slopes to the lovely sources of the Comal River, two medium- 

 sized colonies of Pheidole dentata var. commutata Mayr. They were under 

 stones about sixty feet apart. One contained ants of the typical dark variety 

 of the species, while both the soldiers and workers of the other colony were 

 decidedly paler. On lifting the stones my attention was arrested by several 

 very large and conspicuous individuals with huge gasters, moving about 

 among the workers and soldiers of normal dimensions. Unfortunately I 

 failed to preserve any living specimens at that time but collected instead a 



1 Cambridge Natural History. Insects, Vol. I, 1895, p 550. 



2 Die Psychischen Fahigkeiten der Ameisen. Zoologica, Heft 26, 1899, pp. 1-132, Taf. 

 i-iii. 



3 Recherches sur le Developpement postembryonnaire, Tanatomie et les mcEurs de I'Encyrtus 

 fuscicoUis. Recueil Zool. Suisse, V, 1891, pp. 435-534, pi. xx-xxv. 



* Recherches sur la Biologie et le Dgveloppement des HymSnopteres Parasites. I, La 

 Polyembryonie Spficiflque ou Germinogonie. Arch. Zool. Expgr. (4), II, 1904, pp. 257-335, 

 pi. ix-xiii. 



6 Sviluppo dell' Ageniaspis fuscicoUis (Dalm.) Thorns. Rendic. R. Accad. Lincei, XV, 1906, 

 pp. 650-657. 



