230 MB. p. B. BBDDAH.D ON NEW BABTHWOKMS. [Mar. 19, 



The length of a specimen selected for measurement was 40 mm. 

 by 3 mm. in diameter. 



Number of segments 95. 



The prostomium is complete. Dorsal pores are visible. 



The clitellum occupies segments xiii.-xvii., and is not developed 

 all round the body. 



There are no papillae of any kind that I could discover. 



The gizzard is in segment vi. The last heart is in xii. The sperm- 

 sacs in xi. 



The sacs of penial setae are, as in Microscolex papillosus, of 

 enormous length. They measure 6 mm. and extend through 

 fourteen segments. The sperraiducal glands, on the other hand, 

 only extend through six segments. The penial setae have the same 

 form as in Microscolex ptapillosus. 



The spermathecae are also exactly as in that species. 



Hah. St. 193, Tierradel Fuego, Puerto Pantalon ; St, 187, Tierra 

 del Fuego ; St. 140, Uschuia ; St. 178, Navarin, Porto Toro. 



(3) Microscolex papillosus, n. sp. 



Of this rather remarkable new form three individuals were taken 

 in forest at Uschuia. 



The largest specimen measures 87 mm. ; its diameter is only 

 3 ram. ; the number of segments 95. The worm is thus a slender 

 species. 



Like so many of the American species of Microscolex, it is pig- 

 mented ; but the pigmentation is not very great, the anterior end 

 of the worm dorsally being alone much coloured. The colour is 

 purplish. In one individual there was no pigment. 



The setas are quite strictly paired. The prostomium is not 

 continued by furrows over the entire buccal segment ; it extends 

 over about half of it. The clitellum occupies segments xiii.-xvi. ; 

 it is complete. On the sixteenth segment in the middle line is 

 a deep hole, looking as if caused by the contraction of the stout 

 muscles connected with it and passing to the dorsal parietes. 



Tliis is very characteristic of the species, and was not confined 

 to the largest individual which was selected for dissection. It lies 

 in the clitellar region, but is lined by a strong tall epithelium, 

 which is not glandular like that of the clitellum. 



There seem to be no dorsal pores. 



The genital papillae are very numerous, an unusual state of 

 affairs in this genus. There are at least six of them round 

 somewhat translucent areas, possibly rather sense-organs than 

 glandular papillae, upon the middle of segments xii.-xii. ; I am 

 inclined to think that others were to be distinguished upon the 

 clitellum. But I did not, with a view of preserving the specimen 

 intact, submit this part of the body to a microscopical examination. 

 In another specimen there was an additional papilla upon xiii., a 

 smaller median papilla upon xv., and a pair upon xvi., one on either 

 side of the median depression. 



The male pores upon segment xvii. are very prominent ; each is 



