EARTHWORMS 423 



marked difference in size between the anterior and the posterior setae found elsewhere 

 among the examples ; and it had a median papilla upon the 7th segment, this segment 

 being occupied in others by a pair of similar papillae. These characters however do 

 not always coincide, for in my original paper describing the species Perichaeta barba- 

 densis, I recorded the fact that in an individual with two pairs of spermathecae there 

 was a single median papilla upon the 7th segment, as well indeed as another occupying 

 a similar place in the iSth. To make a species of this worm we must characterise it by 

 the two pairs of spermathecae and the median anterior instead of paired anterior 

 papillae, as well as by the greater uniformity in the size of the body setae generally. 

 In view of the variations which occur in individuals which no one would thus separate 

 it seems to be unreasonable at least in the meantime to do this. 



I may perhaps be allowed to point out that 1 was justified on the facts as originally 

 known in making a new species for these worms. They then differed as far as was 

 known from Perichaeta haioayaiia in having setae upon all segments of the clitellum, in 

 possessing anterior as well as posterior genital papillae, and finally by generally having 

 but two pairs of spermathecae. 



I shall now consider the probable identity of these forms with Perichaeta morrisi. 

 This species was originally distinguished from its allies by the following assemblage of 

 anatomical features : small size, 52 mm. with however 93 segments ; two pairs of 

 spermathecae in 6, 7 ; median papillae in 7, 8 ; glandular bodies in the neighbourhood 

 of the male pores were not seen to open by papillae ; but such glands are usually 

 associated with papillae. Rosa' described later examples of what appears to be the 

 same species. His examples were larger (up to 80 mm.); setae present on all of the 

 segments instead of only 16 ; clitellum occupying the whole of segments 14 — 16 

 instead of stopping towards the middle of 16 ; glands near male pores ; in one example 

 a median papilla upon [8 was noted ; others showed variation in the anterior papillae, 

 in one a median papilla on 6 and a pair on 7 closely approximated in the middle line 

 with a more lateral pair on the same segment and a median papilla on 8. Another had 

 median papillae on 6 — 8 ; a third one only on 7. Dr Rosa also found, though it was in 

 a rudimentary condition, the septum separating segments 8, 9. 



I have been able to compare with these descriptions some worms from Hong 

 Kong among my stores of Oligochaeta. I examined many of these which 1 refer to 

 the same species. 



One was 93 mm. long ; two papillae lay by each male pore, and on 7 there were 

 three papillae, one median and two lateral. Setae were present on all segments of the 

 clitellum. In other characters I found no differences from Perichaeta viorrisi as 

 described. 



In a second individual of 80 mm. length there were also two pores in the neigh- 



' Lombrichi raccolti a Sumatra &c. Ann. Mus. civ. Geneva ser. 2a xvi. p. 516. 

 F. H. II. 55 



