Fauna of the Morrow Group 
163 
Horizon and locality. Hale formation: East Mountain, Fay- 
etteville, Arkansas (Station 136). Brentwood limestone: vicin- 
ity of Fayetteville, Arkansas (Stations 134, 135, ?148, 152, and 
153) ; Sawney Hollow, Oklahoma (Station 210). Kessler lime- 
stone: near Brentwood, Arkansas (Station 144). Morrow for- 
mation: near Ft. Gibson (Stations 296 and 303), Choteau (Sta- 
tions 297, 298, and 302), Hulbert (Station 299), and Gore 
(Station 304), Oklahoma, 
Productus gallatinensis Girty 
Plate IX, figures ^-Sb. 
1899. Productus gallatinensis. Girty, Mon., U. S. Geol. Surv., No. 32, 
p. 533, pi. 68, figs. 7a-c, lla-d. 
Madison limestone: Yellowstone National Park. 
1903, Productus gallatinensis. Girty, Prof. Paper, U. S. Geol. Surv., No. 
16, p. 361, pi. 3, figs. 4-8a. 
Hermosa formation: San Juan region; Ouray, Colorado. 
Crested Butte district, Colorado. 
The fossils from the Morrow group referred to this species 
are apparently identical with the forms from the Hermosa lime- 
stone described and figured under this title. Their identity with 
the types from the Madison limestone is, however, not so clear. 
It is possible that the Pennsylvanian species is not the same as 
the Mississippian one and in that case it would seem likely that 
the forms from the upper horizons should be referred to P. 
hoonensis Swallow. 
Horizon and locality. Hale formation: East Mountain, Fay^ 
etteville, Arkansas (Stations 136 and 137). Brentwood lime- 
stone: vicinity of Fayetteville, Arkansas (Stations 138, 148, and 
?153). Kessler limestone: East Mountain, Fayetteville, Arkan- 
sas (Station 209). Morrow formation: near Wagoner (Station 
294), Choteau (Station 298), and Gore (Station 304), Oklahoma, 
Productus fayettevillensis n. sp. 
Plate X, figures 5-6. 
Description. Shell of medium size, transversely sub-oval in 
outline, wider than long, length of hinge-line a little less than 
greatest width of valve. Dimensions of the holotype, an aver- 
age specimen, are: length from hinge-line to anterior margin, 
16.1 mm. ; distance from umbonal region to anterior margin. 
