140 Transactions. — Zoology. 



It seems to me that the differences enumerated in the 

 table are sufficient to raise our Chatham Islands form to the 

 rank of a distinct species, for there are other details in which 

 the two disagree. The thickened septa in the Japanese species 

 are behind segments 5 to 13, whereas in ours only those 

 behind 6 to 12 ; and even the first and last of these are not 

 so thick as the rest of the group. The chaetae of the dorsal 

 and ventral couples are equally spaced. The intestine in the 

 Japanese form is said to commence in the 14th, while I find 

 it beginning in the 20th. But most striking of these details 

 is the point of entry of the sperm-duct into the duct of the 

 spermiducal gland. Further, the geographical relations must, 

 in the case of earthworms, have considerable weight in deter- 

 mining the question : for there is little, if any, communication 

 between Japan and Chatham Islands. 



5. Microscolex huttoni, n. sp. 



Seventeen specimens collected in the " bush," Chatham 

 Islands ; preserved in formol. 



Colour. — Pinkish — i.e., unpigmented — with light-brownish 

 clitellum. 



Dimensions. — The usual length is 3^ in., though one 

 reaches 5 in. Tbe diameter is -^ in. {i.e., 90-125 mm. by 

 3 - 3 mm.). It is thus a slender worm, and contains 130 seg- 

 ments. Even the longest has only 136. 



The prostomiwn is prolonged over a quarter of the length 

 of the buccal segment. 



The chcetce are arranged in four rather distant couples : 

 ab = cd < V, D = 3| cd, L = 2 ab ; or, put into proportionate 

 numbers, measured on the flattened skin, ab = cd = 3, V = 4, 

 L = 5, D = 8. 



The clitellum is saddle-shaped, extending over segments 

 14 to 17 ; but the glandular thickening ceases ventrally at the 

 level of chaeta b. 



Genital Pores. — Each male pore is situated on a papilla 

 on segment 17 ; from each pore there protrudes a long delicate 

 penial chaeta, which, when magnified, is seen to curve rather 

 abruptly at the free end, while the extreme tip is recurved to 

 form a hook ; it is without ornamentation. The spermathe- 

 cal pores (two pairs) are invisible with a lens only ; they lie, 

 however, in the grooves 7/8 and 8/9, at the level of chasta b. 



In addition to these structures, there is a series of paired 

 ■" tubercula pubertatis," or genital suckers. Each "sucker" 

 is a circular glandular pad with a central depression ; they are 

 all situated in line with, and behind, chaeta a, close to the 

 hinder margin of the segments, so as to appear at first sight 

 intersegmental. The usual uumber, so far as can be judged 

 from seventeen individuals, is three pairs, which are on 



