THE TOP-KNOTS. 91 



whose distinctive mark is the orange-coloured 

 centred black spot, and ventral fin separated from 

 the anal. But whether this is an invariable distinc- 

 tion, or sufficient to constitute it a distinct species 

 from MuUer's Top-Knot, we are not prepared to say. 

 Both Muller's and Block's are remarkable for the 

 underlapping of the ends of the dorsal and anal fins 

 across the root of the tail underneath. We have 

 only once taken any of the Top-Knots elsewhere in 

 the West, and that was off the west coast of the 

 Lewis, where it wanted the brilliant spot and was 

 apparently unmistakably Muller's of Couch. 



Dr. Day calls our species, without doubt, Rhombus 

 punctatus, of which it may therefore be a small 

 local variety. 



We would recommend the class to the attention 

 of our friends during the coming summer at the 

 coast, when we hope to hear that some addition 

 has been made to our knowledge of their habits, 

 appearance, and distribution. We should be glad 

 to have an opportunity of comparing specimens 

 from the Clyde of any of the species with those of 

 our neighbourhood. 



All the rays of this fish are split half-way up, and 

 thenceforth are double to the extremity. 



