224 REPORT OF THE COMMISSIONERS OF 



Gaston to the Craig Brook station in Maine. The length of the trout ranged from 4 

 to 4^ inches; they are now 10 inches long on the average, and weigh many times as 

 much as they did a year ago. None of them have at any time yet shown a red lateral 

 band such as is present in the rainbow, and they are further distinguished by the 

 presence of white tips on the ventral and anal fins ; the dorsal also has a small white 

 tip. They ha\"e been kept almost from their arrival in salt water, and could not have 

 been kept in the warm Croton water in June. The salt water never rose above 71^4" 

 Fahrenheit, and continued at this high temperature only ten days. 



46. Salmo irideus {Gibbons). R.viXBmv Tkout. — Trout of this species have 

 been received from the South Side Sportsmen's Club at Oakdale, Long Island ; the 

 New York Hatchery at Cold Spring Harbor, Long Island, and the Caledonia station 

 of the New York Fish Commission. The large fish never stand transportation well 

 when ice is used to cool the water. They frequently injure their eyes so that they 

 become blind soon after the end of the trip. They are inveterate fighters, and the 

 strongest invariably rules the rest. Contrary to what has been stated heretofore, they 

 will not endure high temperatures as well as brook trout. 



47. Salmo fario {Liuinciis). Browx Trout. — This is one of the earliest species 

 of trout to be placed in the Aquarium, and has shown remarkable hardiness in cap- 

 tivity. A large female was received from Mr. E. G. Blackford in April, 1896, and 

 placed in a salt-water tank, where it remains now (November 27, 1897), and gives 

 every indication of perfect health. During most of the time the fish has been in salt 

 water, but at certain intervals fresh water is substituted for a short time, especially 

 when symptoms of fungus make their appearance. Liver and live killifish have been 

 used for her food. Last November she excavated a shallow depression in the gravel 

 bottom and deposited a lot of eggs. The species is extremely shy, and never seems 

 to lose its fear of the attendants. 



48. Salmo (Hybrid = fario -f- fontinals). Hybrid Trout. — In a paper pub- 

 lished seven years ago, the writer stated as a result of his studies, that when a large- 

 scaled trout is crossed with a small-scaled one, the hybrid will be large-scaled which- 

 ever way the cross be made. The hybrid between the brown trout and the brook is a 

 large-scaled form, and it is sterile as far as reported. The Aquarium has had this 

 hybrid from the South Side Sportsmen's Club, and from the New York hatcheries at 

 Cold Spring Harbor, Long Island, and Caledonia. It is always a strikingly handsome 

 fish, and grows to a large size ; but it is far less hardy than either of its parents. The 

 cross has always been artificially made, and never occurs naturally. Two specimens 

 studied gave the following measurements in inches : 



