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XXL — On the Anatomy of Ocnerodrilus (Eisen). By Frank E. Beddard, M.A., 

 Prosector of the Zoological Society of London, Lecturer on Biology at Guy's 

 Hospital. (With a Plate.) 



(Read 2nd March 1891.) 



The worms which form the subject of the present communication were forwarded to 

 me, in a living condition, from Kew Gardens. 



I have received lately a considerable number of living Oligochaeta from those Gardens, 

 through the kindness of Mr Dyer, # who permitted me to have the earth arriving from 

 different parts of the world in the Wardian cases, in which plants are packed for travel- 

 ling, thoroughly sifted, with a view to preserving the worms which had been accidentally 

 included. By these means I have succeeded in obtaining some very interesting new 

 forms, as well as a number of others which are still imperfectly known. The species which 

 I describe in the present paper appears to be a new species of Eisen's genus Ocnerodrilus. 

 The genus Ocnerodrilus was formed by Eisen in 1878 [1] for a small worm found 

 in Fresno County, California. The specimens were all met with in " an irrigation box," 

 where they were found crawling among the algae which covered the boards. It is 

 evidently, therefore, aquatic in its habits, but Eisen contrasts its slow movements with 

 the rapid swimming of Lumbriculus and Rhynchelmis, comparing it in general appear- 

 ance with a small species of Lumbricus. 



My own specimens, eight in number, came from British Guiana in a Wardian case 

 containing plants ; they also presented the appearance of a small Earthworm rather than 

 of any Lumbriculid with which I am acquainted. The colour, which seems to agree 

 with that of Ocnerodrilus occidentalis, is reddish, caused of course by the blood seen 

 through the transparent body-walls, which are, however, rather thick for so small a 

 worm. These specimens may be terrestrial in habit, but there was a Pachydrilus in the 

 same earth with them, which may perhaps indicate an especially moist locality. As, 

 however, Allurus can live equally well in earth and in water, it is not surprising to 

 meet with other forms which possess the same power of adapting themselves to different 

 circumstances. The size of the species, when contracted by the corrosive sublimate with 

 which they were preserved, is shown in fig. 5 ; it is therefore somewhat smaller than 

 Ocnerodrilus occidentalis. During life, it is almost unnecessary to state, these dimen- 

 sions were considerably exceeded by the power of extension of the body which the worm 

 possessed. 



* I desire ulso to record my appreciation of the careful way in which Mr Crisp, one of the employes at Kew, has 

 sorted out and transmitted to me these aud other specimens. 



VOL. XXXVI. PART II. (NO. 21 . 4 Q 



