BRACHIOPODA. 97 



Surface marked by fine concentric striae which are often crowded into prominent 

 wrinkles towards the front. Shell-structure finely punctate. The interior shows a 

 short terebratuliform loop, which is abruptly recurved at its lower extremities." 



Remarks — -The Cranaena romingeri from Missouri are somewhat more ventricose 

 than average and most of them have no indication of a sinus. The preservation is 

 not such as to retain the loop so that it can be definitely determined. 



Occurrence — Mineola of Montgomery and Ralls Counties. 



Superfamily Spiriferacea 



Family Atrypidae 



Genus Atrypa Dalman 



A try pa gregeri Rowley 

 Plate 18, figures 7-9 



1900. Atrypa gregeri Rowley, Am. Geologist, XXV, p. 264, pi. 5, figs. 9-11. 

 1909. Atrypa gregeri Greger, Am. Jour. Sci., XXVII, p. 376. 



Rowley's description — "Shell ovoid, gibbous, length and breadth nearly equal. 

 Brachial valve almost circular, convex. Pedicle valve convex, with an extended, 

 slightly incurved, perforate beak. Neither mesial elevation nor sinus is apparent on 

 any of the five specimens examined. 



Surface marked by numerous, fine radiating striae crossed by rather strong con- 

 centric lines of growth. 



It may be possible that an examination of the inside of the valves of this shell will 

 place it in some other genus, but externally it is apparently very close to Atrypa." 



Remarks — Atrypa gregeri has about four plications per millimeter, while small 

 specimens of A. reticularis (Linnaeus) have about two. The fineness of plications is 

 about the only distinguishing character of the species. In lacking fold and sinus it 

 agrees with many specimens of A. reticularis (Linnaeus). 



Occurrence — Rare in the Snyder Creek shale of Callaway County. 



Atrypa reticularis (Linnaeus) 



Plate 21, figures 6 and 7; plate 23, figures 12, 13 



1767. Anomia reticularis Linne, Systema Nature, ed. XII, 1, p. 1132. 



1842. Atrypa chemungensis Conrad, Jour. Acad. Nat. Sci., Philadelphia, VIII, p. 265. 



1842. Atrypa chemungensis Vanuxem, Geol. New York, Rep. Third Dist., p. 182, fig. 4. 



1858. Atrypa reticularis Hall, Geol. Survey Iowa, vol. I, part II, p. 515. 



1867. Atrypa reticularis Hall, Pal. New York, IV, pp. 316-321, pi. 52, figs. 1-3, 7-12; 



pi. 53, figs. 3-19; pi. 53a, figs. 22, 23. 

 1894. Atrypa missouriensis Miller, Indiana Dept. Geol. Nat. Res., 18th Ann. Rept., 



p. 315, pi. 9, figs. 19-21. 

 1897. Atrypa reticularis Schuchert, Bull. U. S. Geol. Surv., 87, pp. 154-155. 



1901. Atrypa reticularis Kindle, Indiana Dept. Geol. Nat. Res., 25th Ann. Rept., p. 

 598, pi. 6, fig. 10. 



1909. Atrypa reticularis Greger, Am. Jour. Sci., XXVII, pp. 376, 377. 



1909. Atrypa reticularis Grabau and Shimer, North American Index Fossils, I, p. 310, 



figs. 389a, b. 

 1911. Atrypa reticularis Cleland, Wisconsin Geol. and Nat. Hist. Surv., Bull. 21, 



p. 74, pi. 13, figs. 12, 13. 

 1913. Atrypa reticularis Prosser and Kindle, Maryland Geol. Survey, Middle and 



Upper Devonian, pp. 183-185, pi. 16, figs. 4-6; and Clarke and Swartz, pp. 



586-587, pi. 55, figs. 6-11. 



