Presidential Address. T. Petch. 25 
Pseudomicrocera. It consists, in its fully developed form, of 
a stalked pezizoid disc, which bears ’usariwm conidia. I propose 
to make this the type of a new genus, Discofusarium, with the 
species Discofusarium tasmaniense. Mr Brittlebank has also 
furnished me with specimens which show that the perithecial 
stage of this species is a Calonectria. 
Of the remaining species of Muicrocera, parasitic on scale 
insects, Microcera Parlatoriae Trabut*, Muicrocera Tonduziw 
Pat.t, and Microcera curta Sacc.{ are Fusarium. Microcera 
vectispora Cooke and Massee§ is Tetracriwm, the conidial stage 
of Ophionectria (? coccicola); Cooke protested|| that he made 
this species only in deference to the current opinion that minute 
differences in the spores were specific, but it would be difficult 
to imagine anything more different from Microcera than this. 
In 1918, Stevenson] described another type of conidial fungus, 
Tubercularia coccicola, which was found on scale insects, Lepido- 
saphes and Hemichionaspis, in Porto Rico. Specimens have 
been kindly furnished by Stevenson, and they are, as far as 
can be determined, identical with a similar conidial fungus 
which occurs on scale insects in Ceylon and India. In the two 
latter countries, however, the perithecial stage has been found, 
and this, as might be expected, is another species of Nectria, 
which will be named Nectria Tuberculariae. 
Another undescribed species of Nectria has been found cn 
Mytilaspis on Citrus in Ceylon. This will be described as Nectria 
barbata. Its conidial stage is unknown. 
Historical sequence has been discarded in this account, in 
order to bring together the recorded species of the same genus. 
We must now go back to 1886, when Ellis and Everhart** 
described a species, parasitic on scale insects on orange trees 
in Florida, as Ophionectria coccicola. Ellis and Everhart dealt 
with the perithecial stage only; Zimmermannff, who found the 
same species on Parlatoria in Java, supplied a description of 
the conidial stage in 1901. This conidial form is a very curious 
production. It consists of a short parenchymatous column, 
surmounted by a white, usually conical, head of conidia. The 
conidiophores are short moniliform chains of a few cells. At 
the apex, each conidiophore bears a cluster of two to five, long, 
lanceolate conidia, which falls off as a whole. The detached 
conidium is compound, and consists of a basal cell, the apical 
* Bull. Agric. Alger et Tunisie, 1907, p. 32. 
+ Bull. Soc. Myc. France, xxviii (1912), p. 142. 
ft Ann. Myc., vit (1909), p. 437. § Grevillea, xvr (1888), p. 4. 
|| Vegetable Wasps and Plant Worms, 1802. 
4 Annual Rep., Insular Exp. Sta., Porto Rico for 1917. 
** Journ. Myc., 11 (t886), p. 39; ibid., p. 137. 
tt Centralb. f. Bakt., Abt. 2, vir (1901), p. 872. 
