HYPOCRELLA AND ASCHERSONIA. 187 



and seven on species of Lecanium. From the specimens left 

 by him these included Asch&rsonia 'placenta, A. confluens, A. 

 hypocreoidea, A. samoensis, A. Coffeee, and A. marginata. 



Since 1904 species of Aschtrsonia have generally been 

 described as occurring on scale insects. Hennings described 

 Aschersonia parasitica on a coccid on Andropogon in 1904, 

 Patouillard described Aschersonia pisiformis on a Coccus on 

 Cocos nucifera in 1906, while Reorders in 1907 enumerated 

 Aschersonia Eugenise, Aschersonia Henniiigsii, and Aschersonia 

 lecanioides as parasitic on scale insects. The position at the 

 present day is that stated by Thaxter : " There can be no 

 question in the mind of any one who has had an opportunity 

 to examine them in a fresh condition that they are strictly 

 entomogenous, like the species of the genus Hypocrella, which 

 have a similar habitat on various species of scale insects." 



The recognition of the entomogenous nature of Hypocrella 

 is of later date. The first species described as parasitic on a 

 scale insect wsis HypocrellaRaciborskiihjZimm.eTTasinn in 1901. 



Parkin in 1904 was of opinion that the genus Hypocrella 

 was one which might eventually be shown to be of common 

 occurrence on scale insects. He recorded two collections 

 parasitic on Lecanium, now known to be Hypocrella ceramichroa 

 and H. Revneckiana, respectively, and a third gathering on 

 Chionaspis vitis, which is not now available ; this last deter- 

 mination was, perhaps, erroneous, as no species has since been 

 found on Chionaspis. * 



Raciborski, in 1906, stated that he had usually found 

 Hypocrella parasitic on scale insects, and recorded that habit 

 for Hypocrella Amomi, H. convexa, and Barya salaccensis 

 {H. Racihorskii) . But Koorders, in 1907, described Hypo- 

 crella Gremae, H. Mollii, and H. Engleriana without reference 

 to any host, except the plants on which they occmred. 



In 1909 von Hohnel added three species, Hypocrella 

 cretacea, H. hispora, and Fleischeria sclerotioides, to the list of 

 those known to be parasitic on scale insects. 



In many gatherings the development of the fungus on the 

 scale insect is quite obvious, as the stroma does not completely 

 cover the scale, but forms a ring round and over the outer 

 edge of it. This occurs, as far as has been observed, only 



