RELATIONS OF KIDNEYS IN HALIOTIS TUBERCULATA. 77 



Notes on the Relations of the Kidneys in 

 Haliotis tuberculata, etc. 



By 



II. J. Flewre, B.Sc, 



U.C.W., AberystwyUi ; Fellow of the University of Wales. 



With Plate G. 



NuMEEOUs accounts of the structure and relations of the 

 kidneys of Diotocard Gastropods have been written, chiefly 

 by workers interested iu the question of the homology of the 

 Monotocard kidney, but in the various descriptions occur 

 several contradictory statements, which naturally lessen the 

 value of current theories on the subject. The present paper 

 is the first-fruits of a study of the gastropod kidney, and it 

 endeavours, by throwing new light on oue or two disputed 

 points, to help on the solution of this difficult problem. 

 There are also brought forward certain suggestions concern- 

 ing the kidney and reproductive organs of Monotocards which 

 I feel convinced should be studied together; these sugges- 

 tions are naturally extremely tentative, pending further 

 woi'k. In making this communication I wish to express my 

 deep indebtedness to Professor Ainsworth Davis, whose 

 advice and encouragement have alone made this research 

 possible. 



Haliotis possesses structures right and left of the peri- 

 cardium (8), which, notwithstanding various views concerning 

 their relations, are generally allowed to be the representatives 

 of the right (7 r) and left (7 l) kidney of the primitive Dioto- 



