Dr. F. E. Be (Ma vd on the Genus Trichodrilus. 227 



XXVIII. — On the Genus Trichodrilus, and on a British 

 Species of the Genus. By Frank E. Beddard, D.Sc, F.R.S. 



Through the kindness of Sir S. F. Harmer, K.B.E., F.R.S., 

 I received in the middle of March a number of specimens of 

 an Oligochsetous Annelid in a living and quite active con- 

 ditio)! . These were sent to Sir S. F. Harmer by Mr. Charles 

 Candler ; and that gentleman had received them from the 

 Rev. B. Barton, in a well in whose garden they occurred "in 

 enormous numbers/' The locality whence they were obtained 

 is Pulham St. Mary, Norfolk. 



The general aspect of these worms was that of a Tubificid, 

 and they showed the same habit of collecting together into 

 balls, from the mass of which the tails of the individual worms 

 protruded and waved in the surrounding water. A more 

 careful examination, however, showed that the species was 

 not a Tubificid, but a Lumbiiculid. Having ascertained this 

 much, it appeared to me that 1 should probably find them to 

 be identical with another Lumbriculid, found also in a well 

 and in a neighbouring county, and also forwarded to me by 

 Sir Sidney Harmer in the year 1908*. 



This latter worm was found in a well on the property of a 

 gentleman resident near Cambridge. 



I was able to give some account of it in a communication 

 addressed to the Zoological Society of London, referred to 

 below, and to show that this worm from Cambridge was 

 undoubtedly a close ally of the species Phreatothrix pragehsis, 

 described a good many years ago by Prof. Vejdovsky from a 

 well in the city of Prague f- It appeared to me, however, 

 that the species from Cambridge should be assigned to a new 

 species, and this conclusion is accepted by Mr. Southern \. 

 There is no doubt, however, that the examples from Pulham 

 are not referable to the genus Fhreatothrix sensu stricto (I 

 reserve for the present a consideration of the definition of the 

 two genera concerned), but are clearly to be placed in the at 

 least nearly allied genus Trichodrilus. This will be apparent 

 in the ensuing description, which is based upon an examina- 



* " A Note on the Occurrence of a Species of Phreatothrix (Vejdovsky) 

 in England, and on some Points in its Structure," P. Z. S. 1908,'p. 365\ 



t " Ueber Phreatothrix, erne ueue Gattung der Limicolen (Ein Beitrag 

 zur Briinnenfaima von Prag)," Zeitschr. wiss. Zool. Bd. xxvii. 187(F 

 p. 541. 



J " Contributions towards a Monograph of the British and Irish 

 "Oligochseta," Proc. R. Irish Acad. vol. xxvii. sect. B, no. 8, 1009, p. 119 



15*. 



