322 THAXTER. — MONOGRAPH OF THE LABOULBEXIACE^. 
strongly inward, tapering slightly to the blunt unmodified tip. Spores 35 X 3 ft. 
18-28 u. the stalk 90-101 1 X 20 ft. Receptacle 30-40 X 18 \u Appendages 150-200 
60-90 
On the thorax, prothorax and adjacent legs of Stilicus angularis Lee, on the right side; Arlington 
Mass., June. 
typ 
other genus. It has been found only once in company with Corethromijces near the pond in the Arlington 
Park, where its host occurred in great abundance concealed in piles of dry melon stems. It may be men- 
tioned that what appears to be the same species as well as certain others nearly allied, were found by me 
on species of St Hints near Buenos Aires; but these forms have not as yet been carefully examined. In 
habit it resembles Rkadhumyces, but differs in having free antheridia. As above mentioned the generic 
reference must be regarded as merely provisional. 
RHIZOMYCES Thaxter. 
The two additional species of this genus herewith illustrated indicate that, although its appendage- 
characters are well defined, the presence of a penetrating rhizoid, which occurs in the type and suggested 
the generic name, is not of generic value; since in R. ctenophorm the plant is attached by the usual foot. 
The same condition is seen in Dimeromyces and in Ceraiomyccx, which further illustrate the unimportant 
nature of the rhi/.oidal character. The species thus far observed all occur on the very peculiar flies belong- 
ing to the Diopsidse, all of which are characterized by the possession of stalked eyes. It is uncertain, how- 
ever, whether all the infested specimens belong to the genus Diopsis, since these insects are largely unde- 
termined in the collections examined. 
Riiizomyces ctenophorus Thaxter. 
Further material of this species was found in the Berlin Museum on African species of Diopsis; 
No. 852 from Usambara; No. 861 from Zanzibar, and No. 853 from Wangunga. Although the species 
varies considerably in the length of its perithecial stalk-cell, and in the development of its appendage 
which may be much shorter than in the specimen illustrated in my figure, the characters seem otherwise 
quite constant. 
Rhizomyces gibbosus Thaxter. Plate LI I, figs. 22-23. 
Proc. Am. Acad. Arts and 8cL, Vol. XXXVI, p. 400. March, 1901, 
General habit more or less sigmoid. Perithecium amber-brown, concolorous, with its relatively 
large basal cells, from which it is hardly distinguished, asymmetrically inflated, bent, and tapering some- 
what distally; a subtermimd abruptly rounded enlargement, beyond which the short asymmetrical tip 
bearing 
s being otherwise 
unmodified: stalk-cell hyaline, variably, sometimes greatly elongated, separated from the basal cells by 
e more or less distinct constriction. Appendage nearly hyaline, except the small deep brown sterile basal 
cell, the remaining cells, three to seven in number, bearing short one- to two-celled branches distally and 
laterally on which the free flask-shaped antheridia are borne singly or several together. Receptacle 
-hort and stout, the upper cell several times as large as the basal cell, which appears to penetrate the 
host dm . tly by means of a rhizoidal apparatus. Spores about 35 X 3 /*. Perithecium, including basal 
85-108 
00-100 X 13-20 }i. Appendage 05-110 a. Total length to tip of 
perithecium 180-325 n. 
o„ °^ the UPl>er SUrfaCe " ear the tip of thc a,,dom ™ of a species of Diopm. Berlin Museum, No. 
8o0. Tanga, Africa. 
pe 
ioru 
from an examination of the types, but in all cases they were broken in removal. 
if its 
dent 
