ENTOMOPHTHOREAE OF THE UNITED STATES. 185 



host, and extends on either side usually so as to invert the wings, turning them upside 

 down (fig. 377) . The color of the mass is more livid than is commonly the case in Em- 

 pusae and shows no variation towards a greenish hue. The conidia are very variable, 

 usually strongly bent, and are readily distinguished by their neck-like basal portion. The 

 secondary conidia of the second type are remarkably regular in shape (figs. 362-365), 

 and of a type which differs widely from that of the primary spores. 



A somewhat remarkable degeneration of the conidiophores was observed in, I think, 

 three instances. The specimens in which this occurred were noticeably different in ap- 

 pearance from the usual conidial form, having a milky color and not presenting the usual 

 appearance of luxuriant growth. On examination the white substance in these speci- 

 mens proved to be composed of hyphae that had for the most part already broken up into 

 short pieces which were seen to produce at one extremity (figs. 366-367) the singular 

 bodies shown in figs. 368-69, of which the mass covering the insect was chiefly made up. 

 These bodies, which are about the size of the conidia, are almost invariably in the form of 

 an irregular kind of cross, the latei-al outgrowths appearing at variable distances from 

 the extremities of the body; but always of about the shape represented in the figures 

 referred to. I saw no sign of any germination in them, though I was unable to make 

 proper cultivations, and I cannot explain their occurrence unless it be due to a degener- 

 ation of the mass of conidiophores, which subsequently attempt to fulfil their oflBce in 

 this peculiar fashion. The specimens occurred in the usual situations in company with 

 the normal type, and the cause for the degeneration, if it be such, as well as for the pecu- 

 liar shape of the resulting bodies is not apparent, nor have I ever seen any condition re- 

 motely resembling this in other Empusae. 



In the formation of zygospores it should be noted that, unlike the preceding species, 

 the conjugating hyphae are rarely, if ever, septate near the point of union, and are very 

 irregular, running into attenuated branches. The production of a spore from each of 

 the gametes (fig. 369) was sometimes noticed as well as the occurrence of double spores 

 (fig. 373a) apparently formed side by side. In one instance (fig. 368) conjugation 

 seemed to have occurred between the apices of hyphae and not by the usual 8pirogyra- 

 like method. 



Empusa (Entomophthora) gracilis nov. sp. 

 PL 21, iigs. 379-391. 



Conidia slender, subfusiform, with a neck-like papillate basal poi-tion and attenuated 

 apex; strongly curved, rarely straight, containing large oil globules. Measurements 

 7-9 X 30-45,y, average 40 x 8//. Conidiophores digitate, coalescing over host in a white 

 mass. Cystidia of rare occurrence, rounded at the apex. Secondary conidia like the 

 primary; or nearly spherical, papillate. Besting spores unknown. Host attached to 

 substratum by rhizoids. 



Host. Diptera: on very minute gnats. 



HaUtat. CuUowhee, ]!^. C. 



Like E. variabilis, with which it is commonly associated, this species seems to attack 



