560 



OLIGOCHAETA 



thing in B. beddardij I am inclined to think that it will prove universal. Plagio- 

 chaeta seems to be the only other AcanthodrUid (see Benham, 19) with calciferous 



pouches of this kind. Michaelsen has remarked that, frequently, calcareous 

 concretions are only found in the first pair. 



