266 BULLETIN OF THE BUREAU OF FISHERIES. 



Our experiences at Pablof Falls showed that " tickling trout" is as possible in Alaska as in England. 

 While fishing from a ledge out near the middle of the falls we noticed some trout resting in a relatively 

 quiet pool part way up the falls. By reaching one's hand into the water and carefully touching a fish 

 near the tail, then moving the hand forward, gently rubbing the belly and side, and then closing down 

 upon the fish when the hand reached the head, it was possible to lift the fish out of the water without 

 disturbing any of the others. In this way we secured quite a number for our creel. At first they were 

 quite heedless of the hand, but when one became alarmed and, being very slick, got away, all the others 

 in the pool were apt to become greatly disturbed and scurry away pellmell, going down to the foot of the 

 falls. 



The ovaries of all of these trout were quite small and immature, and this was evidently not their 

 spawning season. It is doubted whether their efforts to ascend these falls were actuated by a desire to 

 reach their own spawning beds. The only rational explanation of their running upstream at this time is 

 that it was for the purpose of reaching the spawning beds of the salmon that they might feed upon the 

 salmon eggs. 



Family 14. THYMALLID^E. The Graylings. 



37. Thymallus signifer (Richardson). Alaska Grayling; "Tdhseh" (Indian name). (PL xli.) 



Very abundant in the headwaters of the Yukon. July 18 to 20 numerous specimens were collected 

 in Tagish Arm near Caribou Crossing and from Kilbourne Creek, a small stream flowing into Tagish 

 Arm. Others were seined in the outlet of Lake Bennett, north of the station at Caribou Crossing. At 

 Lake Bennett, July 20 and 21. several small examples were seined near the head of the lake and several 

 larger ones were taken with the fly. One particularly fine example 1 no. 2928). )•"> inches long and weighing 

 1 pound and 2 ounces, was taken on the hook near the railroad station at Lake Bennett. A special 

 agent of the Yukon and White Pass Railroad caught several in a small lake near Log Cabin, which is 

 between Lake Bennett and Caribou Crossing. The fish is said to occur also in Lake Atlin and in Forty- 

 mile Creek, in which it is reported to reach a very large size. 



The grayling is probably of wide distribution in northern Alaska, particularly throughout the 

 Y'ukon basin. Mr. Frank Hess, of the Geological Survey, reports it from Sinuk River, about 35 miles 

 northwest of Nome, and he was informed that it occurs in the same river 70 miles northwest of Xome. 

 He found it also in Kuzitrin River 35 miles northeast of Council, in Xiukluk River at Council, in 

 El Dorado Creek (a tributary of Noxapaga River) 125 to 150 miles northeast of Nome, and in the 

 Kugruk River 110 to 120 miles north of Nome. On August 9 he saw them spawning in streams 40 miles 

 north of Fairbanks. It was found also in Kugruk River (a different stream flowing into Kotzebue 

 Sound) by Mr. Fred H. Moffit, of the Geological Survey. Mr. Frank C. Schrader found it in 1902 

 in Colville River and in other streams and lakes of that region. Mr. Walter C. Mendenhall. also of the 

 Geological Survey, says that grayling may be found in all of the clear- water streams of the Kobuk Valley. 



Mr. F. W. Nelson, of the Biological Survey, reports the grayling from a small stream flowing 

 into the Arctic Ocean just north of Cape Lisburne, about halfway between Kotzebue Sound and Point 

 Barrow. This stream is only 12 to 15 miles long and the grayling were seen in a small pool about half- 

 way up the stream. They were only a few in number and were adults 12 to 15 inches long. According 

 to Mr. Nelson, grayling occur in all tin- streams entering Norton Sound; also in the upper tributaries 

 of the Y'ukon some 30 to 35 miles northeast from St. Michael. They do not occur in the streams down 

 in tin- flats, but up in the hills they are in every clear stream. Dolly Varden trout are most abundant 

 in the larger streams, grayling in the smaller ones. 



The examples taken with the fly at Caribou Crossing and Lake Bennett varied in length from 4.5 

 to 15 inches. The respective lengths in inches of 27 specimens measured are as follows: 4J, 4f, 5f , 6, 

 6J, 6i, 7. 7, 7J, 7|, 7-rt, 7f, 8, 8, 8J, 8J, 8J, 8J, 9. 91. 10. 10, 10}, 11. llf, 13}, and 15 inches, the average 

 being nearly 8.5 inches. 



The example from which the painting was made was 12i inches long and was obtained at Caribou 

 Crossing in August, 1903. 



The 15-inch example (no. 2928) from Lake Bennett was described in life as follows: 



Head 5.25 in body; depth 4.28; eye 4 in head; snout 4.6; maxillary 6; mandible 2; dorsal 21; 

 anal 11. the last ray broad and firm; scales 10-93-10. 



Body elongate, compressed, highest about the origin of the dorsal, from which the contour slopes 

 gradually to the slender caudal peduncle: head small, somewhat pointed: mouth terminal, moderate. 



