560 DR. L. ORLEY. 



worm, cut through the middle, forms a new tail with shortened 

 somites. In autumn more worms with regenerated tails are 

 found than in the spring. Once I found, in October, out of 

 fifty specimens, thirty with regenerated tails. The tail is very 

 brittle, and the reason is very likely to be found in the irregular 

 arrangement of the muscle-bundles. 



In company with Criodrilus there lives a very interesting 

 Earthworm, AUolobophora dubiosa, Orley, which has 

 nearly the same habits. 



Amongst the Hirudinea, species of Aulostoma and 

 Nephelis are their greatest enemies ; these swallow three or 

 four Criodrili at a time. 



[For the explanation of figures 1 to 8, Plate XXXVIII, 

 illustrating Dr. Orley's paper, see p. 570.] 



