ENTOMOPHT MORALES 297 



the surface of the host is reached and penetrated. A branching 

 conidiophore thus results, each branch of which abjoints termi- 

 nally a single uninucleate conidium. 



These observations indicate that the earlier usage of Nowa- 

 kowski in applying the names Empusa and Eyitomophthora to 

 species with unbranched and branched conidiophores respectively 

 was probably in the main phylogenetically sound, and it is not 

 unlikely that later students will return to it. However, the 

 monograph of Thaxter has long been the standard treatment of 

 the group, and the writer prefers to follow it in incorporating 

 all the species in the single genus Empusa. Departure from this 

 nomenclature at present would be premature, and result in chang- 

 ing various well known names. In any case additional species 

 must be investigated cytologically before the nuclear condition 

 of the conidium can be said to have unquestioned taxonomic 

 value. 



Thaxter's use of the generic name Empusa in preference to 

 Entomophthora will be questioned by some students in the light 

 of present rules of nomenclature. Although Empusa is the older, 

 its earlier use in the orchids holds the possibility of confusion 

 in the event of its future resurrection there. It has not seemed 

 necessary in view of this somewhat unstable situation to use the 

 family name Empusaceae or the ordinal name Empusales. 



The genus Empusa, as here treated, is by far the largest 

 genus of the family. Only four species were known to occur in 

 the United States before Thaxter's monograph appeared. He 

 described a total of twenty-six. At present approximately forty 

 species are known. 



The genus Tarichium Cohn (1875: 58) was based on the resting 

 spore condition of an unknown species of Empusa. There is no 

 reason, therefore, for recognizing it as a distinct genus. 



The fungus described by Krassilstschik in 1886 as Tarichium 

 uvella, and in 1888 redescribed by Sorokin as Sorosporella agro- 

 tidis, has been referred by various authors to the Entomoph- 

 thoraceae. Recently it has been shown by Speare (1920: 399) 

 to belong instead to the verticilliaceous hyphomycetes. 



The green muscardine fungus, Metarrhizium anisopliae 

 (Metsch.) Sorokin, which has been incorporated by some students 

 in the Entomophthoraceae near Empusa is here excluded from the 

 family. It apparently (Stevenson, 1918) belongs near Peni- 

 cillium. It is an important parasite of many insects, some of 



