PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 639 
4 mile west of U. S. Highway 11, on the north bank of Middle River, Staunton 
(15’) Quadrangle. 
Discussion.—This is a small species, represented by specimens of poor preser- 
vation. The specimens indicate a species so at variance with F. basalaris that a 
different specific name was thought to be warranted. The species is characterized 
by soft, rounded outlines and elliptical form with numerous costae marking the 
fold, sulcus, and flanks. It resembles R. multicostata but differs in size, less 
elongate outline, and somewhat wider fold. Rostricellula basalaris is more tri- 
angular and has more distant and coarser costae and is not likely to be confused 
with R, elliptica. 
ROSTRICELLULA MAJOR (Raymond) 
Plate 130, H, figures 38-42 
Camarotoechia major RaymMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 369, 1905; Ann. 
Carnegie Mus., vol. 7, No. 2, p. 226, pl. 34, figs. 11-14, I9QII. 
Type.—Holotype: Carnegie Mus. 2171. 
Horizon and locality—vValcour formation in New York: At Cystid Point, 
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle. 
Same formation in Vermont: From a small peninsula off the west shore of 
Providence Island, Plattsburg (15’) Quadrangle. 
ROSTRICELLULA MINNESOTENSIS (Sardeson) 
Plate 131, A, figures 1-7; plate 139, A, figures I-11 
Rhynchonella minnesotensis SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 333, pl. 4, 
figs. 21-23, 1892. 
This species is characterized by fairly large size and solid, robust form. It has 
an apical angle of slightly more than 90°, rounded sides, and a truncated front. 
The fold has 4 costae, the sulcus 3 costae, and the flanks are marked by 6 or 7 
costae. 
The valves are of subequal depth and fairly deep; the profiles are moderately 
convex. The brachial umbo is sulcate, and the 2 median costae do not equal the 
elevation of the lateral costae until about the middle of the valve. The tongue 
of the pedicle valve is fairly long, but the fold of the brachial valve is low and 
flattened in profile. 
Measurements in mm.— 
Brachial 
Length length Width Thickness 
Hypotype (1i7artoa) wie. Jat 16.3 11.6 15.0 11.2 
i CLIG2LOD You, he Jose Meas 12.0 10.6 12.9 8.3 
Types.—Figured hypotypes : 117219a,b, 118035. 
Horizon and locality.—Platteville formation (McGregor member) in Wiscon- 
sin: On Highway 81, 1 mile northwest of Ellenboro, Lancaster (30’) Quad- 
rangle ; Janesville and Beloit, Rock County ; Mineral Port, Mineral Point (30’) 
Quadrangle; Dodgeville, Iowa County. 
