THAXTER. — MONOGRAPH OF THE LAHOULUKNIAORE. "203 
Hy 
pjH'Il 
lied 
as from other localities in North and South America, I have seen this sjiceies 1 >ut once. 
CHITONOMYCES IVyritsch. 
The additions to this genus have not been very numerous sin. the publication of my monograph, 
in part because no special effort has been made to obtain them, and in part for the reason that small 
exotic Dytiscidse do not Appear to be well represented in the collections c\ainiin d. Moreover, after tin- 
host has been mounted and has become well dusted, it is almost absolutely impotsihh to s<< the -mailer 
forms. The genus is no doubt a large one, and species an' sure to be multiplied when the trophal forms 
can be examined fresh or in alcohol. Nevertheless a few very characteristic forms are herewith illus- 
trated, among which C. psittacopsis and C. Buttardi are among the most singular yet discovered. A 
special interest also attaches to C. Javanicus, since, with C. marginaius and C mrhnunis, it represents 
a small group of species, closely allied and evidently either derived from one another or from a common 
source, and all growing in exactly the same position on the same (left) wing of specie of l.afcophilux. 
No attempt has been made since the publication of my Monograph to determine more exactly tin 
nature of the antheridium which, in most speci< , is so small that it can be detected only with the greater 
difficulty, placed as it is on the side of the individual next the pcrithceinm and thus never visible in pro- 
file. A careful study of the antheridia, in forms like C. rhipicoslmna or C. pnm>\< ■/.*, in which they 
appear to be unusually large, is much to be desired. The close relation of this gnus to Lkmmomyrcs 
in which the compound antheridia are evident, cannot be doubted. 
All 
the species added herewith afford further illustrations of the remarkable constancy with which 
these plants occur in definite positions on the hosts, a condition which is to me quite inexplicable unless, 
as previously suggested, it is brought about by automatic motions of the legs while the in cts are M 
roitu. This explanation, however, seems insufficient to account for the restriction of cighi or nine speci. 
on a single host to a corresponding number of definite positions. 
The two nearly related species, C. Aethiopicm and C. OnHogyri should probably be removed from 
this genus, although very closely related to it. It will be necessary to examine young conditions, however, 
before this can be determined. With the exception of these two forms which occur on Qyrinidn, the 
species of the genus are all found on small water beetles belonging to the Dytiseidie and Haliplidas. 
Chitonomyces Hydropori Thaxter. Plate XXXIV, figs. "•• 
Proc. Am. Acad. Arts and Sci., Vol. XXXVII, p. 32. June. 1!»01. 
Receptacle nearly hyaline, the subbasal cell flattened, many times smaller than the b al cell, sHghtlj 
inflated and distinguished from the cells above and below by slight constrictions; the two cells abov 
subequal, the posterior somewhat broader, and separated from the lower marginal cell of the distal por- 
tion by an oblique curved septum, which overlaps its upper fourth; the si.bter.n.nal marginal ceU often 
nearly as long as the lower, the narrow upper half, or more, of which it overlaps. The lower append.eu- 
late cell rather small, the upper terminal one of the typical form, relatively rather long, distinguished by 
a slight constriction, the appendage extending beyond the tip of the perithedum. Penthecium relatively 
large, its upper half, or more, free, distally broader, the outer margin nearly Straight *ith U M subter- 
minal rounded elevation below the abruptly rounded projecting outer brownish hn^eHs; tin- apex other- 
wise flat, broad, bent outward so as to be slightly oblique, the inner margin below ,. bulging and curved 
r» rithedum 80 
150 
modest us Aube, Caj>e 
opoms 
This 'pecies is distinguished by the broad „ut-turned tip of its ,-ntl,. .-mm and the ^ ' 
cells immediately above the very small subbasal eell. The Flornla spe.imen.s are shelly stnalhr 
