42 Bulletin American Museum of Natural History. {Vol. XXIII, 



the latter alternative. But there is still another possibility which I cannot 

 regard as altogether precluded in the present state of our knowledge, namely, 

 that Wasmann's theory may be too concisely formulated, and that pseudo- 

 gynes may occasionally be produced even in colonies that have never been 

 infested with Lomechusini. This would, indeed, be very probable if, as I 

 have supposed, the pseudogynes arise from female larvae that have been 

 merely neglected by their nurses at a particular stage of development. 



Even more fragmentary than our knowledge of A', cava is our knowledge 

 of the other species of the genus. Wasmann recognizes three additional 

 species from North America : montana Casey ^ from California, caseyi 

 Wasm. from Colorado,^ and sharpi Wasm. of Mexico.^ Many years ago 

 Walker described from Vancouver an Atemeles reflexus * which is probably 

 the same as A', cava, and Fall^ has recently described from southern Cali- 

 fornia a Lomechusa angusta, which is a Xenodiisa and may prove to be a 

 synonym of Wasmann's X. caseyi, the smallest of our species. 



The ethological notes accompanying the descriptions of these various 

 species are very brief. According to Schwarz,^ X. montana has been taken 

 in the nests of Camponotus loevigatus F. Smith, an ant which hardly descends 

 below 6,000 feet in the Rocky Mountains and Sierras, and P. M. Wirtner, 

 O. S. B., according to Wasmann,^ has taken this same beetle in the nests of 

 Form,ica suhpolita in Colorado. X. montana seems, therefore, to be heteroe- 

 cious like X. cava. Father Wirtner also took the type of X. caseyi in the 

 nest of F. subpolita. X. sharpi was found in a nest of Camponotus auricomus. 

 One of the type specimens of X. angusta was taken by Dr. A. Fenyes "with 

 ants in a large oak gall." It is probable that these ants belonged to some 

 form of Camponotus marglnatus as this is, according to my observations, 

 the commonest and most widely distributed ant nesting in oak galls in the 

 southwestern States. If this is the case, and if, as I suspect, X. angusta 

 is the same as A^. caseyi, this species would seem to be heteroecious like X. 

 cava and montana. 



Whether there are any Xenodusce that are regularly or even occasionally 

 moncecious with species of Camponotus cannot be decided at the present 

 time. Wasmann entertains this possibility because pseudogynes of this 

 genus have been described, and their existence would ex hypothesi require 

 the rearing of Xenodusa larvae by Camponotus. Emery has described a 



' Descriptions of North American Coleoptera, I. Bull. Calif. Acad. Sci., II, 1886-87. p. 

 202, 203. 



2 Eine neue Xenodusa aus Colorado mit einer Tabelle der Xenodusa-Arten. Deutsch. 

 Ent. Zeitschr., 1897, II, p. 273, 274. 



3 Revision der Lomechusa-Gruppe, I. c. 



* In Lord, The Naturalist in Vancouver Island and British Columbia, II, 1899, p. 317, 318. 



* List of the Coleoptera of Southern California. Occas. Papers. Calif. Acad. Sci., VIII, 

 1901, pp. 219, 220. 



6 Myrmecophilous Coleoptera, etc., loc. cit., p. 246. 

 ^ZurBiologie der Lomechusa-Gruppe, loc. cit., p. 275. 



