1894.] THE SECBETAET ON A GATJB OE HTDIAX BISON. 249 



way as to produce a result which is approximately bilaterally 

 symmetrica]. Of the general significance of this phenomenon I 

 have spoken in the place referred to. 



It should be observed that this specimen does not at all precisely 

 conform to the principle of symmetry illustrated by the Brill 

 described above. There was nevertheless in it also an imperfect 

 correspondence between the distributions of the spots upon the 

 areas dorsal and ventral to the median axis. Asymmetry, however, 

 was exhibited in the presence of one spot on the dorsal fiu, and of 

 one spot over the dorsal neural spines, that were not represented 

 in the area ventral to the lateral line. 



I am not aware that Flat-fishes having pigment upon their 

 "blind " sides have before been examined with a view to this ques- 

 tion ; and owing to the importance of the matter with regard to 

 the defining of the principles of Symmetry, such an examination 

 should be made in all cases where the presence of definite spots or 

 marks makes the determination possible. 



In contrast with these cases of symmetrical variation were ex- 

 hibited photographs of a sample of Flounders {Platessa flesus) from 

 the shallow water near Bournemouth. In this locality there is a 

 high percentage of specimens having pigment on the " blind " sides. 

 Of a sample of 32 all but 3 were to some extent spotted with 

 pigment. In 5 this spotting was so great as to give them a pie- 

 bald appearance, and of these one was over the greater part of the 

 " blind " side of a full brown colour. No regularity whatever 

 could be detected in the distribution of the pigment. This sample 

 represented the normal condition of the Flounders of the locality, 

 and had not been in any way selected. 



EXPLANATION OF PLATE XVII. 



Kg. 1. View of the " blind " side of abnormal specimen of Rhombus lavis. 

 f nat. size. 



2. Enlarged view of the spot dd. 



3. Enlarged view of the spot vh. 



March 20, 1894. 



Prof. G. B. Howes, F.Z.S., in the Chair. 



The Secretary exhibited a photograph of a young male Gaur or 

 Indian Bison {Bos gaurus) \ forwarded by Major G. S. Eodon, of 

 the Royal Scots Eegiment. Major Eodon had captured this animal 

 when out Bison-shooting in the Neelampattry Hills, in Cochin, in 

 August 1893, and had kindly offered to present it to the Society. 

 The Secretary was now endeavouring to make arrangements for 

 its transmission home. He remarked that no Gaur, so far as he 

 was aware, had ever reached Europe ahve, except the specimen 



» See Blanford, P.Z. S. 1890, p. 592, pi. xlix. 



