NO. 2 BKACHIOPOD SUPERFAMILY STENOSCISMATACEA GRANT 1 37 



Table 30. — Measurements of Coledium undulatum from the Chappel Limestone 



in Texas 



Measurements, in millimeters 



Comparisons. — Coledium undulatum is characterized by its broadly 

 subpentagonal outline, moderately convex pedicle valve combined with 

 very strongly convex brachial valve which becomes increasingly con- 

 vex with overall size of the shell, its numerous fine costae on fold 

 and flanks, short pedicle beak, and total lack of a stolidium or its be- 

 ginnings. It occurs with C. evexum n. sp. in the Chappel Limestone, 

 differing from that species in its larger size, wider outline, shorter beak, 

 and numerous costae on fold and flanks that begin farther posterior. 

 It is larger and has more numerous costae than C. explanatum (Mc- 

 Chesney), C. cestriensis (Snider) or C. obesum (Clark), attaining 

 a size similar to that of C. erugatum n. sp. which has no costae and a 

 narrower outline, or C. torvum n. sp. whose costae are short and weak 

 and outline narrower. It is larger and more convex than C. bowsheri 

 (Cooper) and differs further in its costate flanks. 



Occurrence and abundance. — Chappel Limestone, 0.55 mile N. 39° 

 W. of High Lonesome Windmill, 8 miles southeast of Brady, Bald 

 Ridge area, McCulloch County, Tex. (Cloud loc. TF-406) (200 

 specimens USNM 142505) ; Chappel, north side of draw, 0.6-0.7 

 mile up Honey Creek from county road crossing, 8 miles southwest of 

 Mason, Bear Spring area, Mason County, Tex. (Cloud loc. 417c) 

 (4 specimens USNM 142506) ; on San Saba River, 0.25 mile below 



Fig. 32. — Scatter diagrams of dimensions of Coledium undulatum n. sp. from 8 

 miles southeast of Brady, Tex. 



