NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA — GRANT 95 



Family STENOSCISMATIDAE Oehlert, 1887 (1883) 



[now. transl. et correct. Muir-Wood, 1955, p. 91, ex Stenoschismatinae Oehlert, 

 1887, p. 1304] [= Camerophoriidae Waagen, 1883 {nom. transl. Grabau, 1936, 

 p. 70, ex Camerophoriinae Waagen, 1883, p. 435) ] 



Stenoscismatacea with stolidium incipient, well-developed or de- 

 generate, ranging from Middle Devonian through Permian; early 

 representatives small, smooth, or weakly costate ; later representatives 

 larger, more strongly costate. 



Subfamily STENOSCISMATINAE Oehlert, 1887 (1883) 



[nom. correct. Muir-Wood, 1955, p. 91, ex Stenoschismatinae Oehlert, 1887, p. 

 1304] [= Camerophoriinae Waagen, 1883, p. 435] 



Stenoscismatidae with stolidium incipient or well-developed; shell 

 rhynchonelliform ; costae beginning anterior to beaks. 



Genus COLEDIUM Grant n. gen. 



(Kolos, Gr., stunted; ledion, Gr., little dress) 



Shell small for family, rhynchonelliform, moderately to strongly 

 biconvex ; outline subelliptical to subpentagonal, slightly transverse to 

 slightly elongate ; commissure uniplicate, with fold expressed primarily 

 at anterior, not standing high above flanks, beginning 5-10 mm. ante- 

 rior to brachial beak; sulcus similarly shallow, beginning 5-10 mm. 

 anterior to pedicle beak; costae absent, weak, or moderately strong, 

 occupying fold or fold and flanks, beginning about same distance an- 

 terior to beaks as fold and sulcus, rarely beginning 1 or 2 mm. ante- 

 rior to beaks, rarely bifurcating ; valves overlapping on posterolateral 

 slopes, butting at anterior and anterolateral margins, there slightly 

 protruding in most species ; stolidium narrow, rudimentary, erratically 

 present in some species, absent from others, most common on fold, 

 rare on flanks. Growth lines weak, closely spaced; growth laminae 

 slightly stronger, most frequent near anterior margins, irregularly 

 spaced. 



Pedicle valve somewhat swollen in umbonal region, flatly convex 

 toward flanks, more strongly convex longitudinally through sulcus, 

 edges of flanks not reflexed ; beak short to moderately long, suberect 

 to erect, tightly pressed to brachial umbo in some species and some 

 individuals ; beak ridges normally blunt, rarely sharp ; delthyrium tri- 

 angular, small; deltidial plates absent, or small, normally disjunct; 

 foramen small, slotlike, penetrating apex of beak in some species. 



Brachial valve more strongly convex, normally greatly swollen in 

 umbonal region, crest of fold flatly convex transversely and in profile ; 

 beak short, bluntly rounded, apex within pedicle valve. 



