NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA — GRANT 51 



Measurements. — Dimensions of the holotype and six paratypes are 

 given by Cooper (1956a, p. 524). The average length is about 6 mm., 

 width about 5 mm., and thickness about 4 mm. 



Comparisons. — Psilocamara renjroarum is characterized by its small 

 size, relatively narrow outline, entirely noncostate surface, and its fold 

 that is high at the commissure but does not stand greatly above flanks 

 along its length. Normally it is about half as wide as Camerisma (?) 

 sella (Kutorga) and also differs in its more gently rounded crest of 

 the fold, weaker median trough in the sulcus, and complete lack of 

 costation. It is about one-sixth the size of C. (?) pentameroides 

 (Tschernyschev), and its fold is much lower and has no break in 

 slope toward the flanks. P. (?) athyriformis (Grabau) is about the 

 same size as C. (?) sella, much larger than P. renjroarum, but its as- 

 signment to Psilocamara is uncertain. 



Occurrence. — Pennsylvanian (Des Moines) in Texas and Missouri 

 (localities listed in Cooper, 1956a), about 110 specimens in collection. 



Genus CAMAROPHORINA Licharev 1934 



Camarophorina LICHAREV, B., 1934, Doklady Akad. Nauk, Leningrad, vol. 1, 



No. 4, p. 211, 213. 

 NOT Camerophorina SCHMIDT, H., 1941, Senkenb. Naturfor. Gesell., Abhand. 



459, p. 43 (in Rhynchonellacea). 



Shell small, rhynchonelliform, biconvex; outline elongate to trans- 

 verse, subelliptical to subpentagonal ; commissure strongly sulcate ; 

 fold on pedicle valve beginning 5-10 mm. anterior to beak, not strongly 

 elevated above flanks except at anterior, normally very weakly costate, 

 with costae beginning at beak or near anterior ; sulcus on brachial 

 valve short, beginning about 10 mm. anterior to beak, rather shallow 

 but steeply flexed longitudinally to extend as tongue into arch of fold ; 

 posterolateral edges of valves butting at commissure without overlap ; 

 stolidium absent ; flanks smooth or very weakly costate ; growth 

 laminae weak, irregularly spaced, more frequent toward anterior ; 

 growth lines fine, closely spaced, producing barely visible concentric 

 ornamentation over entire shell surface. 



Pedicle valve somewhat swollen in umbonal region, rather flatly 

 convex longitudinally along crest of fold, strongly convex transversely 

 and from beak to anterolateral flanks ; beak strongly curved, erect or 

 suberect, sharply pointed ; beak ridges rather sharp to poorly defined ; 

 delthyrium small, triangular, partly or entirely filled by brachial beak ; 

 deltidial plates not observed, probably absent. 



Brachial valve strongly convex longitudinally through sulcus, gently 

 convex transversely, midregion somewhat swollen ; apex of beak 

 largely or completely concealed by pedicle beak. 



