PROGRESS IN BIOLOGICAL INQUIRIES, 1935 451 



It was possible, also tliroiigli the oenerosity of Dr. Clark and 

 others to, fly to the Rio Chiriqiii Viejo near the Costa Rican border 

 in sonthwestern Panama, to investigate tlie results of a plant of rain- 

 bow trout made by the Bureau of Fisheries in the upper stretches 

 of this stream in 1925. It was found that the trout were abundant 

 as had been reported by sportsmen. The temperature of the water 

 durino; the several days spent on the stream in February at an eleva- 

 tion of about 6,000 feet varied from 54° F. in the morning to 57° F. 

 in the late afternoon. Based on 45 digestive tracts examined, about 

 90 percent of the food injested by the trout consisted of caddisfly 

 larvae and nymphs. The remaining food included beetle larvae and 

 a few adults, mayfly larvae and nymplis, dragonfly larvae and 

 nymphs, stonefly larvae and nymphs, net-veined midge larvae, a 

 few midgefly larvae, a few adult terrestrial insects, and very few 

 ostracods and amphipods. 



MARINE FISHP^S OF THE GULF COAST 



Systematic studies of the American fishes in general, and (liose of 

 the Gulf coast in particular were continued by Isaac Ginsburg. 

 Special attention was given to the revision of genera of the difficult 

 families Pleuronectidae, Gobiidae, and Cyprinodontidae. These re- 

 visional studies should place the systematics of some of the more 

 difficult marine families on a firm scientific foundation. 



SILVER SPRINGS, FLA. 



During the latter part of August, Dr. Samuel F. Hildebrand spent 

 several days collecting fish in Silver Springs, Fla. Because of the 

 clearness of the water it was found impracticable to collect with a 

 seine dui'ing the day, as the fish were able to see the net and the 

 collectors, and invariably retreated to a safe distance or depth. 

 Consequently most of the collecting was done at night. 



Altogether 25 species of fishes were obtained in Silver S])rings. 

 They consist of 2 species of gars, the bowfin, 2 species of catfish, 

 the common fresh-water eel, a jack-pike or pickerel, the white mullet, 

 (a marine fish), 5 species of sunfish, the large-mouth black bass, and 

 11 species of minnows belonging to 5 difl'erent families. The col- 

 lection, of course, is not exhaustive, but it very probably includes 

 nearly all the regular residents. 



Fishing is ])rohibited in the springs and large fish are fairly 

 immerous, it being possible to see the entire population even to a 

 de])th as great as 50 or 60 feet, because of the clearness of the water. 

 Small fish and minnows, however, are rather scarce. Evidently the 

 springs have as large a population of predatory fishes, such as the 

 bass, bowfin, catfish, gars, jack-pike, and sunfishes as can find 

 sufficient food. 



Lake Maffamusheef. — Upon the request of the North Carolina 

 Conservation Commission, Dr. Samuel F. Hildebrand was detailed 

 to make an investigation of Lake Mattamuskeet to sui)plement an- 

 other investigation made earlier in the year by other representatives 

 of the Bureau (Messrs. Jackson, James, and Surver). The ])rincipal 

 purpose of the investigation was to determine the comparative 



