FISHES OF MISSOURI AND ARKANSAS. 
131 
This is one of the handsomest of the darters. I take pleasure in naming it for 
Julia Hughes Gilbert. (Mrs. Charles H. Gilbert.) 
29. Btheostoma zonale (Cope). 
James, not common. Scale 56 to 58. 
30. Btheostoma nigrum (Rafiuesqiie). 
North Fork of White Elver; not common. 
31. Btheostoma cceruleum (Storer). 
James, not common. Scales 44-J6. Bryant’s Creek, not common. Scale 37-40. 
Var. spectabile (Agassiz). 
James, not common. Scales 44. Bryant’s Creek, common. Dorsal IX or X — 
12 to 14. Scales 37 to 40, cheek naked, opercles with few scales. Color in some 
female specimens much as in JE, cceruleum, but darker, mottled, and with the bars 
very indistinct. The stripes on the sides are less distinct, and the bars have a ten- 
dency to form quadrate spots on the sides. 
32. Btheostoma whipplei (Girard). 
North Fork of White Eiver, scarce. 
33. Cottus bairdi Girard. 
.lames and Bryant’s Creek, common. 
VII. — MAMMOTH SPRING. 
Spring River, a tributary of the Black which empties into the White, has its i ise 
in Mammoth Spring, in North Eastern Arkansas. About one-third of a mile below llie 
spring. Spring Eiver receives a tributary known as the Warm Foric. 
From 3J to miles west of Mammoth Spring are English and Myatt Greelcs. These 
creeks unite and empty into Spring Eiver at some distance below Mammoth Spring. 
We collected in all of these streams, and also in a small creek flowing through llie 
town of Mammoth Spring and emptying into Spring Eiver opposite the mouth of 
Warm Fork. 
Mammoth Spring is one of the largest springs in the United States. Its volume 
of water remains quite constant during the entire year, never diminishing more than 
one-sixth in its amount. We reached the town of Mammoth Spring on Saturday 
night. It began raining late Saturday evening and continued to rain most of the 
following day. On Sunday and Monday the water from the spring was very clear, 
on Tuesday and Wednesday quite opaque, aud by Thursday evening it was noticea- 
bly much clearer again. We were told by several persons that it was unusual for the 
water in the spring to become clouded, A dam has been constructed a short distance 
below the spring. The distance between the wheel pits on either side of the dam is 
107 feet. Between the wheel pits the water at the time of our visit was flowing over 
the dam at the dejrth of 1 foot. A large amount of the water was also used to sup- 
ply the fish hatchery. The water in the spring flows from a large fissure at the foot 
of a low cliff. By the construction of the dam a small lake of about; 17 acres is formed. 
The water in the lake at one point near the foot of the cliff is 170 feet deep. 
The Warm ForJc when first seen by us was somewhat muddy and swollen. Its 
current is quite swift, and by four days the water was low enough to permit collecting 
with fair success. The bottom of Warm Fork, except near its mouth, was rocky and 
gravelly. Its temperature above the spring was 75° Fah. Its volume of water was 
