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 Testes in X. Spermathecae in IX, with large stalked 

 diverticulum. Penial setae with spinelets. Hah. — 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, 7a mm.; diameter, 7 mm.; number of segments, 83. Setae distant, 

 the ventral setae converging on segments XIII-XX. Clitellum, XIV-XVII. Dorsal 

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

 in X. Penial setae long and unornamented. Spermathecae small in IX, with tubular 

 diverticulum. Hob. — 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, 93. Setae more closely 

 paired ventrally than laterally. Clitellum, XIII-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 Till, each with 

 two short diverticula. Hah. — 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. 



