30 Dr. W. B. Benham on some Javan Pericheetide. 
anteriorly to the septum, 7. e. in segment vii., the sac, being 
in segment vill. f 
The prostate is relatively small; it measures 4x 3 millim. ; 
so that the general outline is nearly circular; it occupies 
segments 17-19. It is divided into only a few main lobes, 
each of which is rounded distally and notched in a variety of 
ways; the penial duct is short and straight, and opens through 
a feebly marked circular “ bursa.” 
Though this worm bears a general likeness to several other 
species from Java and the neighbouring region, yet on com- 
parison I have been unable to identify it with any of these. 
In general form it recalls P. endica, Horst *, which, however, 
possesses four pairs of spermathecee, and the ventral chete 
are larger than the rest. P. falcata, Horst, from Hast Flores, 
has more numerous (sixty) cheete, and the diverticulum of the 
spermatheca is very much shorter than in my specimens, 
though the two structures bear a close resemblance to one 
another; the prostate is much more deeply lobed. 
P. sumatrana, Uorst tT, is only about half the size of the 
new species, though it possesses about the same number of 
cheete ; the spermatheca appears to be somewhat similar. 
Again, P. Slucter’¢, Horst, from Billiton, is larger, has 
more numerous cheete, which are distinctly closer together 
ventrally ; the spermathece have a terminally dilated diver- 
ticulum; and the prostate recalls that of the worm just 
described. 
All these worms seem to belong to a group of species 
differing from that containing P. Willey’, P. tjibode, &e. 
in the character of the spermathecal diverticulum, and in the 
presence of less numerous chet per segment, as well as in a 
few other points; but these are details, and the two groups 
are not very widely separated from one another. 
EXPLANATION OF PLATE III. 
Pericheta Willey?, sp. un. 
Fig. 1. Portion of the worm, dorsal view, to show banding. 
Fig. 2. Side view of a portion of the worm. The arrow indicates the 
anterior direction. 
‘tg. 3. View of the male pores. 
4ig. 4. A spermatheca from the seventh segment, X 7. 8, sac; d, diver- 
ticulum ; e, terminal saccule. 
* ‘Notes from the Leyden Museum,’ y.; and Beddard, Proc. Zool. 
Soc. 1886 and 1890. 
+ ‘Notes from the Leyden Museum,’ v. 
