6 Mr. Yarrell's Descriptions of three 



coloured and inferior parts by a well-defined boundary line ; the irides are 

 yellowish M'hite ; infra-orbital portion of the head, the operculum, and sides, 

 shining- silvery white tinged with yellow ; all the fins pale yellowish white ; 

 the lateral line descending from the upper angle of the operculum by a gentle 

 curve to the middle of the body, thence to the centre of the tail in a straight 

 line ; the scales of moderate size, marked with numerous concentric striae, 

 and prominent radiating elevated ridges, the central portion of each scale 

 being brighter than its sides, and producing the appearance of shining longi- 

 tudinal lines extending the whole length of the body. The head is small, 

 depressed ; the cheeks flat ; the line of the back but little elevated ; the dorsal 

 fin commences exactly half-way between the nose and the end of the fleshy 

 portion of the tail ; the first dorsal fin-ray is short, the second ray the longest, 

 the last ray double. The mouth is small, without teeth on either of the max- 

 illary bones ; the eye large ; nostrils pierced nearer the eye than the nose ; 

 branchiostegous rays 3, operculum of two pieces. The pectoral fin arises 

 below a triangular plate directed backwards ; the abdominal line moderately 

 convex ; the ventral fins are placed on a vertical line, but little in advance of 

 the anterior portion of the dorsal fin ; the anal fin commences, on a vertical 

 line, immediately under the termination of the dorsal fin-rays, when that fin is 

 depressed ; the first ray of the anal fin is short, the second ray the longest, 

 the last ray double ; the fleshy portion of the tail is long and slender, its rays 

 deeply forked. I can speak with confidence to the differential characters of 

 the Graining and Dace, having been favoured on this occasion with a Dace 

 from the same stream which produced the Graining. The length of the Dace 

 compared to the depth is, as I have stated, but as 4 to 1 ; the back and sides 

 are yellowish olive strongly tinged with blue, passing by imperceptible gra- 

 dations to silvery white beneath ; the lower fins aie pale red ; the pectoral 

 fin not surmounted by a similar triangular plate ; and the radiating lines on 

 each scale are produced by grooved depressions and not by elevated ridges. 

 The number of all the fin-rays is different, those in some of the fins being 

 greater, and in others less. 



D. P. V. A. C. 



Graining 9. 17- 10. 11. 19. 



Dace 12. 15. 9. 12. 19. 



