92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



slopes for overlap by edges of brachial valve, normally exposed by 

 breakage or weathering. 



Brachial valve more strongly convex ; beak covered by pedicle beak ; 

 posterolateral valve-edges thin, commonly broken. 



Pedicle valve interior with large, thin-walled spondylium, sessile in 

 extreme apex, elevated on very low septum toward anterior, extending 

 anteriorly about one-fourth length of valve. 



Brachial valve interior with large, spoon-shaped camarophorium on 

 high median septum, edges of posterior part of camarophorium touch- 

 ing underside of undivided hinge plate, continuing free into cavity of 

 shell, extending forward about half length of valve, anterior of cam- 

 arophorium becoming slightly fluted longitudinally, height increasing, 

 length slightly greater than length of median septum, extending con- 

 siderably farther anteriorly than spondylium of opposite valve ; crura 

 short, extending from anterior edge of hinge plate; intercamaro- 

 phorial plate thick at posterior, very short, becoming thin and termi- 

 nating in apex of valve, entirely absent from some specimens. 



Holotype.— USNM 142061, plate 6, fig. 2. 



Comparisons. — Cyrolexis haquei is characterized by its rather small 

 size, slightly elongate globose shape, narrow outline, moderately high 

 fold, strongly curved pedicle beak, and normally costate fold and flanks. 

 It differs from Terebratula sup erst es Verneuil in its smaller size, 

 higher fold, narrower outline, and costate flanks. It is much larger than 

 Camarophoria parvula Tschernyschev ( 1902, pi. 46) and is much more 

 strongly convex, strongly folded, and has more and sharper costae. It 

 resembles the Timanian species C. netschajevi Tschernyschev in its 

 strong convexity, but differs in its narrower and more elliptical out- 



ABC D 



Fig. 18. — Cyrolexis haquei n. sp., Lower Productus Limestone, Salt Range, 

 Pakistan; transverse sections X4, USNM 142066, each valve cut nearly perpen- 

 dicular to internal structures, the two cuts meeting nearly perpendicular to one 

 another. 



A. Near beaks : top of brachial septum not yet spread to form camarophorium, 

 cardinal process fimbriate. B. Farther anterior, no intercamarophorial plate. C. 

 About 0.5 mm. from brachial valve beak and 0.7 mm. from pedicle valve beak. 

 D. Slightly different angle from fig. C, 0.9 mm. from brachial valve beak, 1.5 mm. 

 from pedicle valve beak. 



