96 Transactions British Mycological Society. 
Of the twenty-nine species enumerated in the foregoing list, 
only nine are prior to the current century. The idea that fungi 
might be parasitic on scale insects and not on the plants on 
which they occurred appears to have spread very slowly, and, 
where the scale insect was not immediately evident, such species 
have been described without reference to their real host. Though 
the list is no doubt still incomplete, an examination of the species 
of Nectria, Sphaerostilbe, Fusarium, Atractium and Microcera in 
Herb. Kew and Herb. British Museum has shown that the 
following species are parasitic on scale insects. 
Nectria diploa B. and C. (1868). Sphaerostilbe fammea Tul. (1861). 
Nectria laeticoloy B. and C. (1868). Atractium flammeum Berk. and Rav. 
Nectria subcoccinea Sacc. and Ellis (1854). 
(1882). Fusarium coccinellum (Kalch.) Thuem. 
Nectria Passerviniana Cooke (1884). (1876). 
Nectria oidioides Speg., myrticola Mucrocerva pluriseptata Cke. and Massee 
Rehm. (1888). 
The following new species are described in this account: 
Nectria Tuberculariae. Podonectria echinata. 
Nectria barbata. Patouillardiella Aleyrodis. 
Calonectria coccidophaga. Fusarium Aleyrodis. 
MICROCERA. 
Desmaziéres described Microcera as clavate, composed of 
almost simple hyphae, and furnished with an external sheath, 
which is toothed at the apex. In his note, he stated that the 
sheath is closely adherent. The spores are fusiform and arcuate. 
The Tulasnes overlooked the presence of the sheath, or if 
they saw it, did not understand that it was Desmaziéres’ velum 
or volva. They stated that Mucrocera differed little from 
Atractium, and that some specimens matched the true Stlbum 
of Tode. From their remarks, and the inclusion of the fungus 
in the genus Sphaerostilbe, it is clear that they regarded Micro- 
cera as composed of parallel hyphae, like the usual Stilbum. 
The fructification of Microcera, therefore, is a synnema, with 
Fusarium-like spores. 
The generic descriptions of Microcera in the various text- 
books of mycology have carried on Desmaziéres’ statement 
concerning the velum, but the fungus has been included in the 
Tuberculariaceae, whereas, in its fully-developed form, it belongs 
to the Stilbaceae. In actual practice, however, any fungus with 
fusarioid spores, which grew on a scale insect, has been assigned 
to Microcera. 
One cannot examine many collections of fungi on scale insects 
from the tropics without noting that there are at least two 
distinct forms of conidial fungi, which have fusarioid spores. 
Parkin appears to have been the first to notice that. He de- 
