The Classification and Distrihution of Earthworms. 235 



an<:»les confluent, surface covered by a coarse pustulation. 

 Cornstones, Herefordshire. 



In conclusion, my most hearty thanks are due to Mr Smith 

 Woodward for the information lie has afforded me regarding 

 the Herefordshire specimens in the British Museum, and to 

 Dr Woodward, F.R.S., for permission to make use of the 

 plaster cast taken from one of these specimens. 



Explanation of Plate. 



In all the figures ilie same letters refer to the same things. 



P.L. postero-lateral angle. P. E. yjostero-external angle. A.E. antero- 

 external angle. P.O. post-orbital angle, A.O. ante-orbital angle. 

 ?;i.o. median occipital, c.o. external occipital, c. central, wi. marginal. 

 pt.o. post-orbital, p.o. pre-orbital. e. ethmoidal. 



Fig. 1. Restored outline showing the arrangement of the plates and lateral- 

 line grooves in the cranial shield of P. Acadicus, Whiteaves sp. 



Fig. 2. The same in another specimen, lateral margins of the shield 

 restored in dotted outline. 



Fig. 3. Sketch of a specimen of the cranial shield of P. Anglicus, 

 Traquair, from a specimen in the Edinburgh Museum, 



Fig. 4. Sketch of a plaster cast of another si)ecimen, contained in the 

 British Museum, the surface ornament being omitted. 



XXV. The Classification and Distrihution of Earthv:orms. By 

 Frank E. Beddaed, M.A., F.R.S.K, F.Z.S., Prosector 

 and Davis Lecturer to the Zoological Society of London ; 

 Lecturer on Biology at Guy's Hospital. [Plates XIIL, 

 XIV.] 



(Read 19th February and 19th March 1890.) 



Part I. — Classification. 



As I have taken pains — in common with most recent 

 writers — to point out that the Oligochieta cannot be divided 

 into two divisions, it may seem irrational to consider the 

 classification of the " Terricolotis" forms apart from that of the 

 " Limicolous'' But as a matter of fact, it seems to me that, 

 although it is quite impossible to contrast two such groups 

 as '^ Oligochoita terricola:'' and " Oli<jocha:ta limicolwl' it is 

 VOL. X. R 



