Gattij }[((iint Laboratory^ St. Andrews. 205 



A deep notch occurred beliind the vent and then a promi- 

 nent point witli the spine followed by tlie anal tin. A 

 marked hollow, as if from former injury, existed at this region 

 on the lett side. 



4. A j)laice 9^ inches in length, and which was less |)lun)p 

 than u^ual, showed a marked concavity behind the j^elvic 

 fins, thus separating the origin of the anal by a larger interval 

 that) normal. I'he upper (right) surface had the ordinary 

 ground-colour, but in addition the whole surface was speckled 

 with boldly marked touches of dark brown pigment, which 

 extended to ail the fins and the tail. Moreover, the entire 

 under surface (left) was even more thickly and conspicuously 

 dotted with specks of the same dark brown piguient, which 

 extended to all the fins and tail. The densest groups of 

 these touches occurred over the opercular region and the 

 abdomen. The ground-colour of this surface was white. 



5. In a plaice about 12 inches long the dorsal (right) 

 surface was peculiarly mottled. The anterior area corre- 

 sponding to the head and most of the abdominal region below 

 (to the right of) the pectoral was of the usual dark tint, as 

 also was the tail and a broad irregular patch extending about 

 3 inches forward, especially on the ventral (right) edge. The 

 rest of the upper surface (with the exception of a patch about 

 1:^ inch by | inch between the two larger areas and ventrally, 

 that is to the right) was pure white, the fins (dorsal and anal) 

 alone showing a little dark pigment. The under surface was 

 pure white. No structural peculiarity was visible externally. 



6. A poorly nourished plaice* about 10 inches in length 

 had the dorsal (right) surface dotted all over with black 

 specks and touches, whilst the ventral (left) surface presented 

 an extraordinary appearance, for it was speckled with dense 

 opaque white areas and small circular patches of white, which 

 invaded likewise the fins and tail. Small black specks also 

 occurred on the head, fins, and here and there over the body. 

 The circular nature of the patches of white and their coales- 

 cence to form larger areas would indicate a condition of things 

 not uncommon in certain affections of the skin in which the 

 sympathetic system of nerves is often specially concerned. 

 Such a condition is manifestly due to more than the action of 

 light, which is inadequate to explain the appearances. A con- 

 sideration of all the circumstances of the pigment in these 

 Pleuronectids therefore points as much to peculiarity of con- 

 stitution and the influence of the sympathetic system of nerves 

 as to the action of light, however important that may be. 



* Mentioned in the lleport S. F. B. for 1894 (published 1895), part iii. 

 p. iM4. 



