Dr. W. B. Benham on some Javan Pericheetidee. 47 
In none of them is the male pore carried by a prominent 
papilla, but the shape of the pore appears to some extent 
diagnostic—that is, 1t may be transverse to the axis of the 
body, as in P, seata, or more or less oblique; and some of 
them are stated to have an “operculum.” I think we may 
leave this feature out of our reckoning. There remains, then, 
but very few points, and these are very small, which serve 
to distinguish these five species. 
I have already suggested that (1) the relative length and 
breadth of the diverticulum, (2) and of the prostate, with a 
careful drawing of the lobes of the latter, (3) the form of the 
prostomium, (4) the general coloration, and (5), within certain 
limits, the size and number of segments of the worm are 
points that should be carefully recorded. Sundry other 
anatomical characters occur in other groups of species of 
Pericheta. What I have written above refers more particu- 
larly to this particular “ capensis” group of species trom 
Java; so closely allied are they that it seems possible that 
their common ancestor is not many generations back. It is 
very difficult to distinguish some of these six species from one 
another by a mere study of the descriptions ; and it may well 
be that two or more are varieties or synonyms. 
I append, therefore, a table (p. 48) illustrating the more 
important apparent differences. 
Pericheta caducicheta, sp.n. (Pl. IIL. figs. 10-12.) 
Three specimens of a rather slim worm possess characters 
which do not exactly coincide with other Javan worms. 
One very striking feature is the absence of chwte on the tenth 
segment in adult worms. Of the three specimens one—the 
most mature—was collected on the voleano Gedeh, the two 
others at Buitenzorg. 
They measure 120, 130, 133 millim. respectively, and the 
diameter is 8 to 4 millim. The body tapers somewhat ante- 
riorly, and the colouring is faint in the preserved specimens. 
There is a dark purplish line along the middle of the back ; 
the dorsal surface of the body anteriorly is light purplish 
brown, and each segment is marked by a white cheetigerous 
ring. The clitellum is darker and browner; there are no 
cheete on it, but three faint light rings; it occupies the usual 
position. 
The following description refers to the largest of the three 
specimens :—It consists of 105 segments, the last three of 
which are without chete. 
