NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA GRANT 91 



pedicle beak that normally presses too tightly to the brachial umbo to 

 allow a pedicle opening, the broad overlap of its valves along the pos- 

 terolateral slopes, the absence of a stolidium, and by its camarophor- 

 ium whose edges may touch the underside of the hinge plate, without 

 support of a strong intercamarophorial plate. Lack of a stolidium and 

 normal lack of an intercamarophorial plate distinguish it from genera 

 of the Stenoscismatidae, although it resembles those genera in its 

 broadly overlapping posterolateral valve edges and strongly curved 

 pedicle beak that closes the pedicle foramen. It differs from most 

 genera of the Atriboniidae in its strongly curved beak, broadly over- 

 lapping valve edges, and weak or absent intercamarophorial plate. 

 Psilocamara Cooper lacks the plate entirely, and its camarophorium 

 does not meet the hinge plate ; that genus differs further in its com- 

 plete lack of costation, its open pedicle foramen, and its butting rather 

 than overlapping posterolateral valve edges. Camarophorinella Licha- 

 rev lacks an intercamarophorial plate, but Cyrolexis differs from it in 

 its stronger convexity, weaker costation, strongly overlapping postero- 

 lateral valve edges, and its undivided hinge plate. 1 



Range. — Cyrolexis is confined to the Permian, apparently ranging 

 through the entire Permian of Asia. It has been found in the Kazanian 

 of the Siberian Far East, in the Lower and Upper Productus Lime- 

 stones of the Salt Range, and species probably belonging to it occur in 

 the Lower Permian of the Urals. 



CYROLEXIS HAQUEI Grant n. sp. 



Plate 6, figs. 1-5 ; figures 18, 19 



Shell strongly biconvex, slightly longer than wide, outline subovate ; 

 commissure uniplicate, with rather high fold only slightly elevating 

 median portion of brachial valve for short distance near anterior, fold 

 normally beginning 8-10 mm. anterior to brachial beak ; sulcus shallow, 

 beginning about same distance anterior to pedicle beak; costae low, 

 sharp at anterior, normally numbering three or four on fold, one 

 fewer in sulcus, commonly same number on flanks as on fold, begin- 

 ning 5-10 mm. anterior to beaks. 



Pedicle valve moderately strongly and rather evenly convex, great- 

 est swelling in umbonal area ; beak erect or slightly recurved, normally 

 tightly pressed against brachial umbo ; large flat areas on posterolateral 



1 Numbering of the figures on the top of page 251 in the Osnovii Paleontologii 

 (Licharev, 1960) appears to be erroneous: figure 293 purports to be a section of 

 Stenoscisma margaritovi (Tschernyschev), but instead is a drawing from 

 Schmidt (1941) of Camerophorina pachyderma (Quenstedt). The section of 

 Camarophorinella caucasica Licharev is figure 292 rather than 294 (cf. Licharev, 

 1936, fig. 4). 



