ENTOMOPHTHOREAE OF THE UNITED STATES. 157 



that the species never produces resting spores and is continued over winter in warmer 

 regions, whence it migrates northward with the flies on the retui-n of summer. This 

 theory, however, does not coincide with my own experience of E. Muscae in this coun- 

 try; since the first specimen which I observM at Cullowliee, where M. domestica liter- 

 ally swarmed, was observed at about the same date at which it usually appears in the 

 •north, namely July first. For three weeks previous to this date I saw no specimens at 

 GuUowhee; and although I have found not the smallest trace of resting spores in a sin- 

 gle instance, it seems improbable that the migration theory can apply to this country at 

 least. 



Giard^ also states that he found resting spores, which were produced externally, oc- 

 curring on specimens found in cool situations; but it is difficult to determine from his 

 description whether the bodies described are true resting spores, and the observation 

 needs confirmation. On plate i, fig. 7 and plate ii, fig. 12, of Lebert's paper,' this author 

 has also figured bodies that seem to be resting spores at an early stage of their formation. 

 The literature concerning E. Muscae is very voluminous; the first description of the 

 form having been given by DeGeer in 1782, according to Brefeld; and for further ref- 

 erences to this literature the elaborate papers of Cohn, Lebert and Brefeld above cited 

 should be consulted. Whether the first supposed description accompanied by a dis- 

 tinctive name, that of Fries,^ really applies to the present species is, I think, extremely 

 doubtful; for the oil globules in E. Muscae could hardly have given rise to the expres- 

 sion "flocci fertiles erecti, .... intus sporidiis globosis referti," whereas in species of the 

 ovispora type, this error of observation might readily have occurred. 



Empusa Culicis A. Braun. 

 PI. U, figs. 10-16. 



Empusa Culicis, A. Braun I. c, p. 105. 



Entomophtliora Culicis, Fresenius I. c. B, figs. 44-45. 



Lamia Culicis, Nowakowski I. c. B, p. 173, figs. 99-114. 



EntomopMhora rimosa, Sorokin I. c. A, p. 146; I. c. B, p. 393, Taf. xiir, figs. 12-19 



(with cut) ; I. c. C, p. 231, figs. 595-596, 575, 576, 603; I. c. D, p. 58, plate i, figs. 



1-13. JS^ec E. rimosa, Schroeter I. c., p. 222. 

 ?8aprolegina minor, Kiitzing I. c, p. 157. 



Conidia bell-shaped or nearly spherical with a broad subtruncate base and sharply 

 pointed apex; 8 X 10/<-15 X 16,«, average 11.5 X 12//,; usually containing a single large 

 oil globule, and surrounded after discharge by a mass of protoplasm. Conidiophores 

 simple or with a tendency to become compound; broad at the apex and gradually taper- 

 ing to a narrow base ; producing white or greenish masses which may or may not coa- 

 lesce over the body of the host. Cysfo'tZi'a present (Nowakowski) . Secondary conidia 

 like the primary, or ovoid with rounded apex and formed by direct budding from the 

 primary spore. Besting spores, azygospores, produced laterally or terminally from hy- 

 phae, spherical, colorless, 25/^ (? in diameter). Host attached by rhizoids. 



' I. c. 



MEMOIRS BOSTON SOC. NAT. HIST., VOL TV. 23 



