538 OLIGOCHAETA 



(jo) Acanthodrilus valdiviensis (new species). 



Definition. Length, 6^ mm. ; diameter, 5 *^*^- S number of segments, 99. No integv/mental 

 pigment visille in alcohol specimen. Prostomium extends over about half of buccal 

 segment. Clitellum extends over XIF-XVII, complete except on XVII. Setae not 

 strictly paired, dorsal a little further apart than ventral. Groove connecting male 

 pores passes to outside of ventral setae of segment XVIII. Oviducal pores in front 

 of and to inside of ventralmost setae. Last pair of hearts in segment XII. The gizzard 

 is in segments V, VI; intestine commences in the middle of segment XVII. The septa 

 dividing segments VII/XVII are thickened. The nephridia have a distinct caecum. One 

 pair of rosettes and testes in X; sperm-sacs in IX, XI j sperm-reservoirs in X. 

 Spermathicae with very large diverticulum. Fenial setae with pointed hooked extremity, 

 just behind which they are somewhat swollen ; behind this again the setae are marked 

 with denticulate ridges. Sab. — Corral, Valdivia {Mr. A. Lane). 



(11) Acanthodrilus dalei, Beddaed. 



A. Dalei, Beddaed, Q. J. M. S., vol. xxx, 1890, p. 433. 



Definition. Length, 40 mm.; diameter, 4 mm.; number of segments, 77. Prostomium 

 completely divides the buccal segment. Clitellum XIII-XVII. Setae strictly paired. 

 Nephridiopores in front of dorsal pair of setae. Sperm-sacs in IX, XI. Gizzard in 

 segments VI and VII, the intersegmental septum being present. Penial setae with a few 

 denticulations near to free end, which is ecS^anded. Spermathecae with a single large 

 diverticulum as big as potich. Hab. — Falkland Islands ; iti fresh water. 



The violet-red colour of this species and its complete prostomium sufficiently 

 distinguish it from its allies. 



(la) Acanthodrilus platyurus, MichaelsenI- 



A. platjrurus, Michaelsen, Arch. f. Nat., 1892, p 226. 



Definition. Length, 180 mm.; breadth, 7 mm.; number of segments, 150. Prostomium 

 complete. Clitellum, XIII-XVII, saddle-shaped. Colour during life, 'flesh-coloured, 

 clitdlum clear brown.' Male-pores upon circular papillae connected by grooves in the 



' As Miohaelsen's single specimen was ' sehr stark erweieht,' and, therefore, necessarily very difficult to 

 interpret, I have not hesitated to expand his description in accordance with my results obtained from the 

 study of other specimens. 



