268 



THAXTER. MONOGRAPH OF THE LABOULBENIACE^E. 



Java, No. 534. In the Sharp Collection; on Pheropsophus sp., from Japan. In the Berlin Museum 

 on P. parallel us Dej., Senegal; on P. Madagascar ensis Nossi Be, Madagascar No. 1004; on P. Kersteni, 

 Aruscha Kisuani, Africa, No. 998; on P. marginatus Dej., Africa, No. 999; on P. fastigiatus, Cape of 

 Good Hope; on Pheropsophus sp., Ceylon, No. 1006. The generic type appears to be an isolated one, 

 and in the Key I have included it in a section by itself, although it is closely related to the Peyritschielleae. 



MONOICOMYCES Thaxter. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 412. April, 1900. 



Receptacle consisting primarily of two superposed cells terminated by a sterile appendage which is 

 variable in character and simple or branched: the subbasal cell producing one, typically two, or in some 

 species several, branches or secondary receptacles, which may consist of one to many superposed cells 

 and may be simple or branched; giving rise to antheridia and perithecia which may or may not be also 

 associated with sterile appendages. The antheridium consisting of four tiers of paired cells, the lower 

 pair forming the stalk, the cells of the two middle pairs producing each a pair of antheridia from their 

 upper inner angles; those of the distal pair cutting off paired sterile cells which correspond to the paired 

 antheridia below, and one or all of which give rise to variously developed, simple, cellular, terminal, 

 sterile appendages: the four pairs of antheridia opening into a common central cavity which discharges 

 between the sterile terminal appendiculate cells. Peritheciuin stalked. 



This is one of the most peculiar and interesting of the genera of Laboulbeniacefe and is extremely 

 variable in the general structure and relations of the fertile branches or secondary receptacles; a varia- 

 bility which is well illustrated by the conditions seen in M. St. Helena and M. Leptochiri. The char- 

 acters of the peculiar antheridium appear, however, to be quite constant in all the species; although, in 

 a few instances, it seems possible that the two middle tiers of cells may produce more than four antheridia 

 each. The curious sterile terminal appendages of this organ are also very variable in their development, 

 both as to number and length, and the cells from which they spring are evidently homologous with the 

 antheridia, which are separated in a similar fashion from the cells below. It will be observed that a more 

 detailed study of these forms has necessitated important modifications in the original diagnosis. 



The hosts of this genus all belong to the Staphylinid.T, a majority of the species occurring on the 

 Aleocharini. 



Monoicomyces HomaloTjE Thaxter. Plate XXXV, figs. 8-10. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 412. April, 1900. 



Receptacle consisting of very small hyaline basal and subbasal cells, the basal cell of the primary 

 appendage short and stout, more or less deeply suffused with blackish brown externally and at the base, 

 the cell above it, bearing two or three branchlets in an antero-posterior plane, the primary (terminal 

 and external) one short and externally suffused with blackish, the lower cell larger and distally inflated. 

 Fertile branches normally two, when the individual is bilaterally symmetrical, rarely three, consisting of 

 a single cell which bears distally an antheridium from its outer and a peritheeium from its inner angle. 

 Perithecium amber-brown, slightly asymmetrical, relatively very large, short and stout; the lower half 

 greatly inflated, generally more so on the outer than the inner side; distally conical, the small tip not 

 distinguished, usually abruptly truncate, the stalk-cell hyaline, narrowing to its base. Antheridium 

 borne on a pair of rather short stalk-cells, the cells of the second tier somewhat smaller and angular, 

 the cells of the third tier somewhat smaller than those of the second, but large and distinct, the paired 

 appendiculate cells separated from the terminal tier, relatively large, all four generally bearing stout 

 finger-like sterile appendages of unequal length. Spores about 35 X 3 [i. Perithecia including basal 

 cells 100-120 X 30-35 p, the stalk-cell 35-40 p.. Antheridia including stalk-cells (not the terminal pro- 

 jections) 70-80 X 30-35 p. Sterile part of receptacle about 70 p. 



On Homalota putrescens Woll., British Museum, No. 412, Azores. On inferior surface of abdomen. 

 On Homalota sp. and Trogophlceus sp. Intervale, N. H., and Kittery Pt., Maine. 



