286 



THAXTER. MONOGRAPH OF THE LABOULBENIACE^E. 



in individuals growing on the integument of host; producing a variable number of fertile branches, 

 disposed subhorizontally on either side of the primary receptacle, the perithecigerous cells, of which there 

 may be from one to six, together with the male individual when present, and the bases of the perithecia, 

 protected by a shield- or shell-like, usually very unequally bilobed cellular upgrowth, rounded or bluntly 

 pointed above, the symmetrically curved successive cells which compose it enormously elongated trans- 

 versely, their lumen scarcely wider than the intervening walls and forming a series of concentrically ar- 

 ranged arcs, the concavities directed downward. Perithecia one to six, commonly five in well-developed 

 specimens, slightly divergent from the median line, long, pointed, tapering from the slightly, more or less 

 asymmetrically inflated base; the distal portion not clearly differentiated, tapering more or less, curved, 

 the slender upper portion bent abruptly inward toward the tip; the pointed apex bent inward, subtended 

 externally by a terminal, slightly incurved, rather slender, bluntly pointed unicellular process, the cells 

 of the cell row which it terminates distinctly larger than the other wall-cells; basal cells somewhat prom- 

 inent. Spores 16 X 1.5 a. Perithecia 145-220 X 30-36 /(, the process 14 /<. Secondary receptacle, 

 including protective shield, in well-developed individuals 125 X 75 fi; in small specimens 35 X 50 

 when vertically developed without shield 35-110 X 18 /«. 



On Periplaneta Americana Sauss. (type form), Cambridge (Mr. Bullard) : Bermuda, Mus. Comp. 

 Zool. On Periplaneta Australasia' Sauss., Bermuda. On Periplaneta spp., Mexico, West Indies, Pan- 

 ama, Brazil, Africa, South Seas, China. All Mus. Comp. Zool. On Stylopyga orientalis Scudd., Boston, 

 Mus. Comp. Zool. 



This common, and in its typical condition, very striking form, appears to be as universally distrib- 

 uted as are its cosmopolitan hosts. It is remarkable for its variability on different hosts or in different 

 positions on the same host. Thus the shell-like shield of the typical form is very frequently absent in 

 specimens on Stylopyga, the form represented in fig. 8, being that which occurs most commonly on this 

 host, while on Periplaneta it is rarely seen. On Stylopyga, moreover, the shield-like covering, when it 

 is developed at all, is usually much smaller than in individuals growing on Periplaneta, and the number 

 of perithecia is usually less. In individuals of the type represented in fig. 8, one often finds instances in 

 which two secondary receptacles have developed from the primary one, each producing its solitary peri- 

 thecium, the two seeming to be paired. 



In the normal typical form (fig. 7) the cells beneath the shield are so closely compacted that I have 

 not been able to satisfy myself as to the exact relations of the structures developed from the female pri- 

 mary receptacle. As in other cases, however, the subbasal cell of the latter seems to cut off a number of 

 cells distally, each of which produces a fertile branch (fig. 12); there being usually five such branches, 

 as shown in the figure; the lower cell, at the left in this figure, being the basal cell of the receptacle from 

 which the foot is broken. If each of these branches produced its single perithecium one would have the 

 condition seen in fig. 7, which is that usually found, the individual bearing five perithecia; one, supposedly, 

 from each branch. Where less than five occur, as often happens, it may be assumed that a smaller num- 

 ber of branches have been developed from the subbasal cell. 



A comparison of figs. 10, 9 and 7 will show how the typically bilobed shield is produced by growth 

 of one of the secondary receptacles upward and outward, on both sides, but much more so on the right 

 than on the left. The form of the perithecium in this species and the position and character of its ter- 

 minal spine, distinguish it from all others, even in cases (fig. 8) where the normal shield has not been 

 developed. The hosts are the common brown and black roaches and the fungus is usually conspicuous 

 from its white color, growing in tufts, especially on the antennae. 



Herpomyces Platyzosteri^e Thaxter. Plate XXXIX, figs. 3-4. 

 Proc. Am. Acad. Arts and Sci., Vol. XLI, p. 310. July, 1905. 



Male individual consisting of four superposed cells bearing distally one or several antheridia. Total 

 length to tip of antheridia about 40 fi. 



