16 ME. r. DAT OlSr VARIATIONS IN TOEM 



the snout, and 1| to If apart. Maxilla reaches to beneath the 

 hind edge of the eye. Posterior edge of preopercle regularly 

 curved, and with a very short but distinct lower limb. As to the 

 form of the opercle, it differs in the different examples : in one 

 that on the right side of the head is not properly developed, 

 leaving a portion of the gills exposed in a similar manner, though to 

 a much less extent than observed in the trout and perch at Malham 

 Tarn in Yorkshire, due, I am informed, to the occurrence of gill- 

 fever in the early age of its existence. The subopercle also differs 

 very considerably in the different specimens. Teeth — in none 

 is there a median row of teeth along the body of the vomer, 

 while the transverse band completing the palatine arch of teeth 

 consists of from 3 to 5. Fins — the dorsal commences slightly 

 nearer the snout than to the base of the caudal fin ; the latter 

 forked. Scales — 40 to 49 rows of scales from the lateral line to 

 the base of the ventral fin ; 21 to 23 rows in an oblique line frorr 

 the posterior end of the base of the adipose dorsal fin downwarde 

 and forwards to the lateral line. Colours — the light sinuous 

 bands of the river-form are very slightly developed in these lacus- 

 trine fish, which are covered with oval or round yellowish spots, 

 one or two of which occasionally run into one another, while red 

 spots exist on, above, and below the lateral line. 



The eggs from which these fish were reared were received 

 direct from the Cold-Spring trout-ponds, New Hampshire, U. S. 



The external appearance of these charr is different in colour from 

 small ones received from Welsh rivers, but more similar to the 

 larger examples. "Whether such is accidental or will be persistent 

 so long as the same influences are at work, only time can decide. 



(4) The appearance of these fish as detained in aquaria where 

 the water-supply is insufficient. By this I do not mean insuffi- 

 cient for life and health, bat for continuation of the species. The 

 example I possess was given me by Mr. J. Carrington; it is 

 9 inches in length, in good condition, and, when received, had 

 brilliant colours. It was reared by the late Mr. Erank Buckland 

 in his tanks at the Horticultural Gardens at South Kensington 

 from eggs received direct from Lake Huron. He presented some 

 young to the authorities of the Westminster Aquarium soon after 

 it was opened ; and the fish on the table is the last which survived,, 

 having died in October 1879 from jumping out of its tank. 



B. x.-xi. D. 13 (^). P. 11. V. 8. A. 10(2^). L. 1.130. 

 L. tr. 49/64. 



