44. Dr. W. B. Benham on some Javan Perichetide. 
in this organ ought to be noted; most authors are content to 
describe the prostate as ‘‘ multilobate,” or some such term. 
Michaelsen * has recently shown that in one and the same 
species, viz. P. indica, the prostate may present differences in 
size, and may even be absent, though the specimens are 
otherwise mature. He had previously noted this lack of 
prostate in P. Hilgendorfi Tt ; and Beddard } records the same 
fact for two other species, P. nipponica and P. masatake. 
The last three species are Japanese (Beddard’s P. rokugo 
appears to be identical with P. Hilyendorfi, Mich.). Michael- 
sen suggests that these species are all closely allied to P. indica. 
- Pericheta sexta, sp.n. (Pl. III. figs. 7-9.) 
Two specimens were collected at Buitenzorg. 
The general colour (in spirit) is a rich brown anteriorly 
and dorsally, becoming lighter posteriorly ; the ventral surface 
is yellowish ; running down the middle of the back is a dark 
line. The chete are set in narrow light (? white) rings, 
which become less marked anteriorly, till in the first six or 
seven segments the rings are scarcely noticeable. A purplish 
iridescence is exhibited by the anterior region of the body. 
The dorsal pores are surrounded by a light ring, or, rather, 
the lips are light (? white), so that the pores are very distinct. 
The clitellum is a much darker brown. This coloration 
agrees with that of P. capensis, as described by Ude, except 
that no mention is there made of the dorsal pores. 
The two specimens differ in length: one is 95 millim. 
long and 4 millim. in diameter, and possesses eighty-two 
segments ; while a smaller and immature specimen consists 
of one hundred segments. 
The small prostomium is dovetailed into the peristomium 
(buccal segment) for about one third the length of the latter ; 
but as there is no transverse boundary, it is difficult to fix the 
actual depth of the dovetail (Ude and Horst say that in 
P. capensis it reaches nearly to the middle of the first 
segment). 
Lhe number of cheete is fifty-six behind the clitellum and 
thirty-eight on the third segment (which closely agrees with 
the numbers tor P. capensis). They form a complete circle, 
though the distance between the two most dorsal chetz 
* “Die Regenwurm-Fauna von Florida und Georgia,” Zool. Jahrb. 
viii. 
+ “Terricol. d. Berliner Zool. Sammlung,” ii. p. 27, in Arch. fiir Natur- 
gesch. 1892. 
} “On some Perichetide from Japan,” Zool. Jahrb. vi. 
