On the StrucfAire of a Nctu Species of Earthworm. 369 



with the view mainly of trying to ascertain whether St 

 Hilaire's theory of " equivalence of organs " affords any 

 satisfactory explanation of these, or any restful point from 

 which they may be considered. I may, perhaps, return to 

 the subject, but at present I wish only to show to the 

 Society two instances — one in the eggs of the Class birds 

 where abnormal growth generally begins, and the other in 

 the case of a kitten. The former consists of two imperfectly 

 developed eggs of the barn door fowl, in which the shells are 

 organically united, a comparatively wide communication 



admitting of the contact of the germinal masses, formative 

 and nutritive. The abnormality of the latter consists in the 

 presence of eight legs, four in the natural position, and four 

 on the back. This instance certainly lies outside of the 

 hypothesis of " equivalence 1 " 



XXIX. Notes on the Structure of a New Sioecies of Earthworm 

 helonging to the Genus Acanthodrilus {E. P.). By 

 Frank E. Beddard, Esq., M.A., F.Z.S. 



(Read 15tli April 1885) 



About a year since I received, through the kindness of the 

 Eev. G. E. risk, C.M.Z.S., of Cape Town, a box containing a 

 number of living earth^vorms. One of these has been al- 

 ready described by me in a paper read before the Zoological 

 Society of London, which has not yet been published. In 

 addition to this specimen — a large worm of 4 or 5 ft. in length 

 — there were a number of other, considerably smaller, earth- 



