NEW ENGLISH GENUS OF AQUATIC OLIGOCH/ETA. 155 



A New English Genus of Aquatic Oligochseta 

 (Sparganophilus) belonging to the Family 

 Rhinodrilidse. 



By 



\¥. B. Bciiliam, D.I$c.(Loiid.)i 



Aldricliian Demonstrator of Anatomy, Oxford. 



With Plates XIX, XX. 



In the summer of 1891, during a stay at the village of 

 Goring-on-Thames, I was on the look-out for Criodrilus, 

 which hitherto has not been found in England. I looked 

 carefully amongst the roots of waterweeds, and in the mud in 

 which these were growing, and ultimately I believed I was 

 successful, for I found a few worms, some three or four 

 inches in length, agreeing closely, so far as regarded ex- 

 ternal character, with C. lacuum, with the exception that 

 the male pore, which is very conspicuous in the latter worm, 

 was not evident. But on further examination the worms were 

 found to present several internal characters which did not 

 harmonise with those of Criodrilus. However, the worms 

 had passed the period of their sexual maturity, so that the 

 generative system was in a degenerate condition, and I was 

 unable to trace the sperm-ducts to a pore. I had therefore 

 to wait till the following summer, when I paid several flying 

 visits to Goring, with finally good results, for I found more of 

 the worms, and this time sexually mature. The genital organs 

 conclusively showed that a new genus was in my hands, be- 

 longing not to the family Lumbricidse, but to the Rhinodrilidse 

 (mihi). 



