90 Olive B. Davies: 



Dorsally there are little papillae, each with two or three fine short 

 hairs; these are piobably sensitive, and are only clearly seen when 

 the living animal is tieated with some foreign substance such as 

 methyl blue. Tlii'ie are also a number of coarser hairs round the 

 anterior and posterior ends. 



There is no clitellum. 



Asexual reproduction, by means of fission, is a marked charac- 

 teristic of this animal; but in this species I could find no case of 

 secondary fission as described in other species. 



Segmentation . 



Segmentation is marked externally by the setae; there being 

 typically a pair of bundles of setae in each segment, but the second 

 bundle marks the sixth segment, there being an asetigerous portion 

 between the first and second bundle. The posterior segments are 

 shorter than the anterior, and, consequently, the setae are closer 

 together. 



Internally segmentation is mai-ke<l by the septa, and the ganglia 

 of the ventral nerve cord. The number of segments varies, as new 

 ones are constantly being added. Asexual reproduction takes place 

 in consequence of this. The shortest animal I met with consisted of 

 eleven segments. 



In eighteen specimens examined : — 



2 having 19 segments, the line of fission was between 10 and 11 



.as not dividint 



The above list seems to point to tlie formation of new segments 

 OH each side of the line of fission, and not only in the postei'i(M- 

 segments, though tlie new segments seem to be foi-med more rapidly 

 at, the ])osterior end. 



Setae. 



The setae, as has been stated before, are arranged in l)undles. and 

 there are typically a pair of bundles in each segment. Each bundle 

 is placed ventro-laterally, and consists of from 8 to 11 setae, 

 arranged in a semi-circle (Kig. vi. (".), except in tlie first bundle, 

 which is straight. (Fig. vi. B.) In connection with these setae 



