British Tuhificida.'. By Rev. H. Friend. 267 



in relation to our British forms. In 1900 Dr. Michaelsen rendered 

 splendid service by the publication of his invaluable work on Oligo- 

 chfeta (Das Tierreich), He does not, indeed, add much to the 

 material supplied by Beddard in this family, except that he gives 

 us a clue to the British species. By a little study of his pages one 

 is able to gather that in 1900 some forty species of Tubificids, 

 ranged under a dozen genera, had been recorded, of which nine 

 only were given for these Islands. Bretscher about the same time 

 described some new species of Annelids belonging to this group. 

 They were found by him in Switzerland, and when we come to the 

 systematic part of our study it will be necessary to refer to him 

 again. 



Ditlevsen published in 1904 an important paper on Danish 

 Oligochiets, and although he makes several mistakes, we owe to 

 him the confirmation of some of Beddard's acute observations on 

 the relation of certain Tubificids to the Naids. It is to be regretted 

 that lie ignored the generic distinctions of other writers, and follow- 

 ing the unfortunate Appendix to Das Tierreich, reduced all the 

 genera to three, viz. Tuhifex, Psammoryctes, and Clitellio. The mis- 

 fortune is the greater since Southern, our only Irish authority on 

 the subject, followed his lead, and has thereby tended greatly to 

 confuse our knowledge. In 1909 Southern described four new 

 species, two of which he places correctly under Limnodrilus, and 

 two under Michaelsen's and Ditlevsen's confusing Tuhifex. He 

 makes the total known British Tubificids in that year sixteen.* 



I have been aided in my researches by a Government Grant, 

 and have been enabled, especially during the past twelve months, 

 to add considerably to our knowledge. These studies were com- 

 menced twenty years ago, but for some time were allowed to lapse, 

 owing to the indifference with which they were received, and the 

 pressure of other work. It will be seen from what follows that 

 our list is already greatly enlarged, while my material shows that 

 several other species yet remain to be described. My position lies 

 midway between that of Eisen and Beddard. The former asserted 

 in 1885 that the class would, he felt sure, in the near future be 

 found to contain thousands of forms. On the contrary, Beddard in 

 1895 (ten years later) surmised that a revision of the genus Limno- 

 drilus would probably reduce the species considerably. Beddard s 

 position is now shown to be untenable. A more careful study of 

 detail and a fuller knowledge of the essential organs has enabled 

 us to distinguish things which differ and make the diagnosis much 

 more complete. 



^ What is needed to-day is not a fusion of genera so much as a 

 fuller study of species from all parts of the world. The foundations 



* Since this paper was read I have consulted the article by Pointner (Zeitschr. 

 wiss. Zool., xcviii. (1911) pp. 626 et seq.), on Oligochc^ts of Gratz, to which refer- 

 ence will be made later. I have also made a study of Claparede's work in Mem. 

 Sc. Phys. Geneva, 1862-3. 



u 2 



