436 Dr. W. B. Benham on some 



connected to the penial duct by three narrow delicate ducts, 

 one from each limb and one from the bottom of the U-shaped 

 gland (fig. 2 a). 



I thought at first, seeing tliat there are several similarities 

 between this and the preceding species, that the spermidacal 

 gland might in reality be of the same shape, but in different 

 positions, in the two worms. But 1 have been unable to 

 place this gland in such a position as in the other worm so 

 as to resemble it ; further, there is no glandular substance 

 below the duct such as there is in P. jampeana. The shape 

 of this gland, in conjunction with the shape of the c^cum, is, 

 indeed, very characteristic. 



The difference in colour, in number of chsetge on the ante- 

 rior segments,, the existence of " gaps " in the circle of chsetse, 

 the difference in the distance of the spermathecal pores from 

 one another, in addition to the more conspicuous difference in 

 the character of the spermiducal glands and of the spermathecse, 

 in these two worms from Janipea would seem to necessitate the 

 formation of two species. Nevertheless for a long time I felt 

 uncertain of the distinctness between them, since both agree 

 in the peculiarity of the caeca, hitherto unrecorded, as well as 

 in character of coloration, difference in size of the two sperma- 

 thecse on one side, &c., and I still hesitate as to whether this 

 second worm may be only a variety of the species P. jampeana, 

 for we know but very little as to the extent of " variation " 

 in Oligochsela ; but from facts derived from the study of other 

 species in greater numbers, as well as from statements by 

 Beddard, Rosa, and others, as to variations in structure in one 

 and the same species, 1 think that it will be the better plan to 

 form a separate species for it. Four worms are collected on 

 an island, nearly the same in size and general anatomy, 

 the points of difference being relatively small, the question 

 arises — does it lead to less or to more confusion to give to 

 each a new name, or to treat them as varieties of one species, 

 till more specimens are known ? If in the future it turns out 

 that P. digitata is only a varietal form or an abnormality of 

 P. jampeana, the name can be dropped. 



The following is the diagnosis of the species : — 



Stone- grey to French grey posteriorly ; more or less mottled 

 with lighter colour ; measures 240 X 15 millira, ; 126 

 or more segments. J\Jale pores wide deep pits j no 

 copulatory papillge. Two pairs ot sperniathecai in 

 viii., ix., with anterior pores; pyriform sac, with 

 long duct, receiving an undulating diverticulum, 

 terminally dilated. Cbsetal ring with slight dorsal 



