TIIAXTIOR. — MONOCKAIMI OF TIIK MOT U? Iv\ I AC I .K. 



Hiiizomvcks ( Kisi'ATt s Thaxter. Plate; MI, fi<^.s. 19 21. 

 PlOO. Am. Acad. Aits and Sri., Vol. XXXV, p. 434. April, 1000. 



Perithecia brownish, dimorphous cither (a) with the inner margin strongly convex, the outer nearly 

 .straight or concave owing to a general outward curvature, tapering to the undifferentiated tip, the apex 

 broad truncate usually symmetrically hisulcate or (1>), the type, straight symmetrical abruptly enlarged 

 below the narrow abruptly distinguished tip: the basal cells well defined nearly isodiametric, the stalk- 

 cell large, as long or longer than the perithecium. Receptacle two-celled, the foot typically modified and 

 blackened, without rhizoids, distally geniculate through a protrusion of the distal cell below the insertion 

 of the stalk-cell and opposite that of the appendage. Appendage erect, sometimes exceeding the tip of 

 the perithecium, consisting of a single series of superposed cells, the three or four lower suffused with 

 smoky brown, the rest subhyaline, each cell except the basal one giving rise directly and externally to a 

 branch, the insertion in successive cells being somewhat to the right and left of the median line so as to 

 form two vertical rows, the basal cells of alternate branches being superposed; each branch consisting of a 

 basal cell externally blackened, which gives rise above to a one-celled short branehlct, bearing usually a 

 pair of long, slender antheridia, the remainder of the branch curved upward blackish brown except its 

 upper margin, and giving rise from its lower (external) side to a series of close-set simple branehlets, 

 black, recurved, more abruptly at the tips which are slightly enlarged and nearly hyaline, the whole sug- 

 gesting the margin of a curled black feather. Spores 20 X 2.8 [i. Perithecia 65-75 X 27-30 /<, the 

 stalk-cell 50-85 ;i. Receptacle 30 /t. Appendages 140-175 //. 



On Diopsis sp., Brit. Mus., No. 739, Natal: Berlin Museum No. 850, Tanga; Xo. 859, Johan Al- 

 brechtshohl, N. Kamerun; No. 851, Usambara; No. 858, Bismarkberg, Togo. All African. 



This species is one of the most striking members of the family from the peculiar ostrich-plume habit 

 of its appendages. There appear to be two distinct types of form in the perithecia even among individ- 

 uals occurring together on the same specimen of the host-insect, as is indicated in the accompanying plate. 

 In the straight form the enlargement below the tip is more or less striking, and specimens occur in which, 

 as in fig. 20, the enlargement is double. These differences were at first thought to be due to differences 

 in the point of view, but an examination of sufficient material would seem to show that such is not the 

 ease. Although it is barely possible that these forms may be distinct, there appear to be no other differences. 

 The penetrating rhizoid which characterizes the other species is absent in the present instance, and is 

 replaced by the normal foot. 



SPHALEROMYCES Thaxter. 



This genus proves to be well represented on hosts belonging to the Staphylinidse and though of a 

 single type, the species are often well distinguished, especially by their perithecia! characters. In a few 

 eases it has been difficult to determine whether forms should be referred here or to Corethromyces, the 

 general characters being superficially similar in the two genera. The seriate antheridia of Corethromyces 

 serve to distinguish it at once, when the material is sufficiently good to show these structures, although 

 even in this respect, simple species of the last mentioned genus, like C. Sfiliri in which the antheridia 

 may be even solitary or serially grouped in small numbers, are not always easily placed. Owing to the 

 fact that the appendages are easily broken, the presence of antheridia has been actually observed in but 

 few instances, and the general structure has of necessity been used in referring many of the species to this 

 genus. 



Sphaleromyces Lathrobii Thaxter. 

 Specimens corresponding in all respects to the type of this species were found in the Hope Collection 

 on a specimen of Lathrobium quadratum Puyk., labeled "Puyk Gyll." Whether this is a locality, and 

 if so where it is, I am unable to say. The host is a European species. 



