69 



The rows of b r i s 1 1 e s are very noticeable ; there are about 40 setae 

 upon each segment in a continuous row. No setae present upon the 

 clitellum. The internal structure resembles that of other Perichaeta- 

 species; the seminal vesiculae, occupying segment X, XI and XII, 

 are rather highly developed. There is a much lobated prostata , opening 

 with a very thick excretory-duct on a large muscular bulbus. 

 Each spermatheca (PI. Ill, fig. 29) consists of a rather large , glo- 

 bular pouch , with a short , thick , muscular duct , which is completely 

 invested with nephridial tubes, and of a single, small diverticulum, 

 connected with the main pouch by a coiled duct. The examples col- 

 lected at the Mount Singalang, in a rather indifferent state of pre- 

 servation, are smaller of size, about 80 mm. in length; the number 

 of setae in each segment appears to be also not so great as in the 

 foregoing, 30 à 36 in a row. 



A large incomplete example, from Singkarah, must also be identified 

 with this species. 



Among the „species dubiae" of Perichaeta, collected by the Sumatra- 

 Expedition, described and figured by my self, there was one example , 

 which undoubtedly belongs to this species 1 ). Though we know other 

 species of Perichaeta from the Indo-malayan region, which possess 

 three pairs of spermathecae , I believe, that the present examples 

 cannot be referred to one of them. P. birmanica Rosa 2 ) appears to 

 be distinguished by a greater number of setae upon each segment, 

 as well as by the shape of its spermathecae ; P. peguana Rosa 3 ), P. 

 carinensis Rosa 4 ) and P. bournei 5 ) are characterized by the presence 

 of copulatory papillae. 



17. Perichaeta sumatrana Horst 6 ). 

 Java: Buitenzorg. 

 Two examples from Buitenzorg probably must be identified with 

 this species. There are no copulatory papillae. The number of setae in 

 the segments in front of and behind the clitellum amounts to 40 à 44. 

 Two pairs of spermathecae are present in segment VIII and IX ; each 



1) Reizen en Onderz. d. Sumatra-Expeditie, Vermes, p. 7, PI. I, fig. 5. 



2) Ann. Mus. Civ. Stor. Nat. Genova, 2d Ser., Vol. VI, 1888, p. 164, PI. Ill, figs. 7—9. 



3) id. id. Vol. X, 1890, p. 113, PI. I, figs. 6—8. 



4) id. id. p. 107, PI. I, figs. 1 and 2. 



5) id. id. p. 110, PI. 1, figs. 3—5. 



6) Reizen en Onderz. d. Sumatra-Expeditie, Vermes, p. 5, PI. I, fig. 2a and b. 



