212 Memoirs of the Indian Museum. [Voi.. I, 



OCTOCH^TUS FERMORI, MlCHI^SN. 



(Plate xiv, figs. 42, 43.) 

 0. /., MICHAELSEN, in Mt. Mus. Hamburg, xxiv, p. 171. 

 Examined a dozen mature specimens. 



External Characters. — Dimensions: lyength 60 — 100 mm., greatest thick- 

 ness about 2^ — 3 mm., number of segments 150 — 190. 



Colour light grey, somewhat yellowish. 



Head epilobous (| — |) ; dorsal appendix of prostomium varying, nearly linear. 



Setae rather small, all at the ventral side of the body, the dorsal median dis- 

 tance being as large as about f of the whole circumference {dd = ca. f u). Setae paired, 

 but not strictly, the lateral pairs being only a little nearer together than those border- 

 ing the median lateral distance {cd = ca. f be). The ventral pairs are at the anterior and 

 middle parts of the body distinctly closer together than the lateral pairs (at the 

 anterior segments ab=^ cd) , at the posterior segments they are less so (at the posterior 

 segments ab =^—^ cd). The ventral median distance is distinctly larger than the la- 

 teral median ones {aa = ca.. f be). 



Dorsal pores indistinct, if not missing. 



Clitellum ring-shaped, from the 13th to the 17th segment ( =5). 



Prostate pores two pairs on the 17th and 19th segments medial from the lines 

 of setae a. 



Seminal furrows curve towards the median ventral line. 



Male pores apparently in the seminal furrows in the zone of setae of the 1 8th 

 segment (not distinctly seen). 



Male area only slightly or not at all depressed. 



Female pores on the 14th segment somewhat medial from the lines of setae a, 

 just before the zone of setae, with a common transversely oval glandular area. 



Spermathecal pores on the 8th and 9th segments in the zones of setae, very 

 close to the ventral median line, sometimes on small papillae which touch each other 

 in the middle line. 



None of the twelve mature specimens showed any copulatory cushions or 

 grooves. 



Internal Anatomy. — The first distinct septum, 4-5, very stout, the following 

 very tender, apparently rudimentary, or quite absent, septum 8-9 about half as strong 

 as 4-5, 9-10 — 11-12 as strong as 4-5, 11-12 half as strong, the following tender. 



Alimentary tract: A big, somewhat oblique gizzard between septa 4-5 

 and 8-9, but not occupying the whole space between them. A pair of very great 

 calciferous glands in the 15th segment, pushing septum 14-15 far forward and 

 septum 15-16 far backward. The calciferous glands are of irregular shape, short and 

 narrow stalked, divided by slight constrictions into some parts. They are not arranged 

 symmetrically, that from one side of the oesophagus crossing its middle line 

 dorsally and extending into the other side of the body behind the calciferous gland of 

 that side. Their internal structure depends on a great number of transverse lamellae. 



