294 MONOGRAPH OF THE LABOULBENIACE^. 
the lutter, I have concluded to separate it, basing the new genus on the greater number and 
different arrang-ement of the small appendiculate cells bearing the lower appendages, the different 
number of wall-cells in tlie perithecium and the fact that three of the lower cells of the recep- 
tacle are superposed. The genus Chitonomyces, although so closely allied, shows no variation in 
these respects. The relation of the mature perithecium to the insertion of the trichogyne, and 
the considerable growth of the former beyond it, recalls tlie similar relation existent in Cera- 
tomyces, while the same is true to a less degree in Chitonomyces. Although these three genera 
arc all aquatic, it does not seem probable that the similarity just referred to indicates any close 
relationship with Ceratomyccs in view of the very different character of the male organs in either 
case. 
As In Chitonomyces, material has been lacliing for a proper study of the younger stages of 
development, and the cliaracter of the trichogyne and antheridium has not been made out. In 
one specimen the procarpe was distinctly seen, and an attempt was made to represent it in fig. 
24, Plate VIII. The trichophoric cell here was large and slightly inflated, lying close beside 
the inner appendiculate cell. The septation in this figure is somewhat misleading from the fact 
that it does not represent what is visible in a single plane. 
There seem to be at least two if not more ascogenic cells in the mature perithecium, 
but theirVstructure and early development have not been seen. It is needless to say that both 
these genera are in a most unsatisfactory condition in so far as concerns their development, and 
■were it not for the discovery of the new genus above mentioned as intermediate between Chit- 
onomyces and Peyritschlclla, their position would be entirely uncertain. The single form 
inhabits species of two genera of aquatic beetles belonging to a family (Ilaliplida^j no other 
members of which are known to be attacked by Laboulbeniaceaj. 
I 
Hydr^omyces Halipli Thaxter. Plate XXVI, figs. 31-33 ; Plate VIII, figs. 22-2-4. 
Heimatomyces Halipli: Proc. Am. Acad. Arts and Sci. Vol. XXVII, p. 32. 
Strongly suffused with dull amber-brown. Perithecia rather evenly inflated, the extremity 
e^-enly rounded, the lip-cells forming a flat, hyaline, abruptly projecting terminal papilla. Basal 
cell of the receptacle rather long, tapering below, its base suffused with blackish, the two cells 
superposed above it broader than long, nearly equal: the terminal cell more or less conical, the 
three lower appendiculate cells nearly as large as the terminal one, and almost completely hiding 
he sub-ternnnal cell on the left side. Spores, 30x3^. Perithecia, 100x35-40;.. Total 
length to tip of perithecium about 150 fi. ■ 
On Ilaliplus ruficollU DeG., and Cne.ndotus muticus Lee, New Haven, Connecticut, and Kit- 
rerj i oint, Maine. 
ho Jorln^tf 7 '"""! ''.^ T ""=™' """"''"' ""'^ '= f™"'' >"™% ™ «'o right elytron of its 
host or on the legs. A single specimen only has been found on Cnomidotus. 
