32 Jordan and Grinnell — New Trout from Upper Santa Ana River. 



ably darker than irideus of the same size, and the other characteristics 

 seem to be constant. 



Comparison. — As compared with Salmo irideus Gibbons, Salmo ever- 

 manni is slenderer, especially dorso-ventrally ; the head is longer, the 

 snout sharper, and mouth larger; the scales are very much smaller, and 

 more numerous, not overlapping; the colors are dull and very dark, and 

 the spotting is heavy. 



Remarks. — On August 17, 1907, the junior author fished down the upper 

 South Fork of the Santa Ana, starting well up in the Big Horse Meadows 

 at about 8,300 feet altitude. A Cincinnati No. 24 double-gut bass hook 

 was used with earthworms as bait. The stream is steep and rapid, there 

 being but few pools with quiet margins. Most of the 30 trout obtained 

 that day were obtained in these pools. Below the meadows a mile or so 

 the canyon becomes extremely steep and narrow; and in this gorge at 

 about 7,500 feet altitude is a series of water-falls, the highest estimated 

 at 18 feet of sheer drop. Twenty-four of the thirty trout were secured 

 above this point, and every one of these belonged to the new species. Five 

 of them were preserved in formalin, changed in a few days to alcohol, and 

 these include the type and cotypes of the present description. The junior 

 author fished on down below the above-mentioned falls, and began to take 

 the typical rainbow trout, Salmo irideus, common in all the lower streams 

 of the region. Six of them were taken that day. During June, July 

 and August, of 1907, 580 trout were caught in the main Santa Ana from 

 Seven Oaks, 5,000 feet altitude, to Big Meadows, 6,700 feet, and in the 

 tributary canyons of Fish Creek, Lost Creek and the lower South Fork. 

 All of these were of the irideus type, which nothing prevents from ascend- 

 ing the main stream from the vicinity of Seven Oaks, which is now freshly 

 stocked nearly every year. But very evidently none has been able to get 

 up over the series of falls towards the head of the South Fork. 



It seems to us, therefore, probable that Salmo evermanni is the older 

 species in the region, and owes its preservation as a distinct species, and 

 perhaps the accentuation of its characters, to isolation afforded by the 

 barrier which prevents the invasion of Salmo irideus from the lower 

 stream. In the remote history of the stream, the falls have doubtless 

 slutted and become more effective, so that the ancestral stock of Salmo 

 evermanni was originally able to ascend to its present remote and limited 

 habitat. 



This interesting species is named for Dr. Barton "Warren Evermann in 

 recognition of his varied and valuable investigations of the American 

 Salmonidx. The figure is by Mr. William S. Atkinson. 



