73 



a violet tint. As proved by transverse sections this colour is due to 

 a dark pigment, which occurs in larges quantities in the" intermus- 

 cular connective tissue, as well in the tranversal as in the longitudi- 

 nal muscular layer, even in that under the peritoneal membrane. 



The longitudinal diameter of the segments in front of the clitellum 

 is nearly equal, however that of the clitellar segments is larger. The 

 first and second segment are not so distinctly separated from each 

 other as the following ones , which is also the case with Perich. capensis. 



The cephalic lobe extends with a broad appendix over about the 

 half of the buccal segment. The clitellum occupies segment XIII — XVII 

 and the ventral region of the next one. The male pores are situated 

 in an obvious pit. The pores of the two pairs of spermathecae, situated 

 in segment VIII and IX, next to the median ventral line, are not 

 visible externally. The dorsal pores commence in the groove between 

 segment IV and V; on the clitellum they are very noticeable, as are 

 also the nephridial pores. 



The number of setae upon the segments in the vicinity of the 

 clitellum amounts to 40 à 50; they are also present on the clitellum. 

 At the dorsal side the setae are separated by an interval about twice 

 as large as that at the ventral side; there is a narrow gap on the 

 median dorsal line. 



In regard of the internal anatomy can be stated , that the 

 alimentary canal of this species much resembles that of Megascolex. 

 The oesophagus extends till segment VI, which is occupied by the 

 gizzard; the gizzard however is imperfectly developed, for as proved 

 by transverse sections, it is only distinguished from the remaining 

 portion of the intestinal canal by the presence of a thick layer of 

 transverse muscular fibres; its epithelium has no peculiar structure 

 and it wants the thick cuticular investment, found in the gizzard 

 of Perichaeta and Megascolex. 



From the various statements about the gizzard of Perionyx-species it 

 may be concluded, that besides by other characters (above referred to) 

 Perionyx also differs from its congeners by a rudimentary gizzard in 

 segment VI (and VII?). Pereieb believed, that in P. excavatus the giz- 

 zard was situated in segment XII ; however it is stated by Rosa that 

 „il vero ventriglio occupa i segmenti 6 e 7 ; esso è piccolo e ha figura di 

 un tronco di cono rovesciato. In segmento XII egli non ha trovato che 

 un semplice rigonfiamento stomacale." P. arboricola, according to the 



