i 4 SCIENCE PROGRESS 



erringly distinguished from a number of other species which 

 more recent authors have created. Thus Michaelsen (5) says 

 it is doubtful whether the Lumbricillus subterraneus of Vej- 

 dovsky can be distinguished from L. lineatus ; while Southern (9) 

 remarks on the difficulty of dividing therefrom the verrucosus 

 of Claparede and Hesse's Pachydrilus litoreus. My own 

 researches (2) tend to show that verrucosus is only a variety 

 of lineatus, and that in a series from the Manchester sewage 

 works which I recently examined with great care all stages 

 between the one form and the other were to be obtained from 

 the one consignment. 



It may at this point, however, be affirmed that the work 

 of Claparede in 1861 laid the foundations for a scientific classi- 

 fication, and since that date an enormous amount of work has 

 been done on the group by such investigators as Bretscher, 

 Eisen, Friend, Hesse, Michaelsen, Southern, Stephenson, 

 Vejdovsky, and Welch. It is not necessary here to discuss the 

 definitions, synonyms, habitats, or distribution of the worms 

 under consideration ; it being sufficient for our present purpose 

 to state that the term Pachydrilus or Pachydrilid is intended 

 to designate the red-blooded Enchytraeids generically known 

 as Lumbricillus and Marionina. 



About fifty to sixty species have so far been described, and 

 although some of these will have to be eliminated there must 

 yet be many other species which have not hitherto been 

 defined. It will be taking a very conservative view of the 

 subject if we say that there are probably no fewer than a 

 hundred species of Pachydrilids in existence, and that the bulk 

 of these are European or even British. 



Seashore Scavengers. — As already indicated, Claparede found 

 his material on the seashore, and this he distributed under 

 five species. One of these, however, had white blood, and 

 was therefore named by him Pachydrilus lacteus, but this 

 proves to be a synonym for the widely distributed Enchytraeus 

 albidus Henle, which is frequently found in such localities, as 

 well as in manure heaps and among vegetable debris inland. 



Any one who will be at the pains to examine the decaying 

 algse found in backwashes on the shore, especially in spring 

 time, will discover that the material is packed with tiny worms 

 from half-an-inch to an inch in length. I have seen them at 

 times numbering not hundreds but myriads, in every stage of 



