464 OLIGOCHAETA 



My account of its anatomy substantially bears out that given by MICHAELSEN, 

 excepting only as regards the form of the prostomium. I found it to completely 

 divide the buccal ring. The colour of the spirit specimens of this species is a dark 

 purple red dorsally. The penial setae are ornamented by serrated ridges at the free 

 extremity. 



(8) Microscolex griseus (NEW SPECIES). 



Definition. Length, 84 mm. ; diameter, 5 mm.; number of segments, 117. Setae strictly 

 paired. Dorsal pores present. Prostomium complete. Clitellum, XIII-XVII. Gizzard 

 in VI. Sperm-sacs in IX, XL Tesles in X. Spermathecae in IX, with large stalked 

 diverticulnm. Penial setae with spinelets. Hal. Valparaiso. 



This is one of the largest species of the genus. It is when alive of a dirty grey 

 colour ; more flesh-coloured in front. There is a median genital papilla upon xvi. 



(9) Microscolex robustus (NEW SPECIES). 



Definition. Length, 73 mm.; diameter, 7 mm.; number of segments, 82. Setae distant, 



the ventral setae converging on segments XIII-XX. Clitellum, XIV XI' II. Dorsal 



pores absent. Proslomium complete. Gizzard in VII. Sperm-sacs in IX, XI. Testes 



in X. Penial setae long and nnornamenled. Spermaihecae small in IX, with tubular 

 diverticulum. Hab. Teja Island, Valdivia. 



There are a number of genital papillae, paired on ix, xv, xvi ; three on xvii, xviii. 



(10) Microscolex michaelseni (NEW SPECIES). 



Definition. Length, 85 mm.; diameter, 3 mm.; number of segments, 92. Setae more closely 

 paired venlrally than laterally. Clitellum, X1II-XVII. Prostomium incomplete. Gizzard 

 rudimentary. Sperm-sacs in XI. Testes in X. Sperm-duct opens behind spermiducal 

 gland on to a groove. Penial setae with spinelets. Spermathecae in VIII, each with 

 two short diverticula. Hab. Magellan's Straits, Uschuia, Navarin Island, S. America. 



This species is aquatic as well as terrestrial. It is quite bleached by alcohol, and 

 has therefore presumably no integumental pigment when alive. The sperm-ducts 

 and glands open on to a crescentic groove, which extends on to segment xviii. It 

 sometimes happens therefore that the male pores are on xviii. 



