54 PALEONTOLOGY OF NEW YORK. 



shell, Spiriferina cristata, Schlotheim, var. odoplicata and S. insculpta* in which 

 it has not been conclusively shown that the median septum exists, though this 

 is a legitimate inference. The gradual assumption of the punctated structure 

 is not so clearly defined among these forms as in the syringothyroid line of 

 development, although one species, the Spirifer transversus, McChesney, from 

 the Chester limestone, is a septate shell in which punctation is but feebly and 

 sparsely developed. 



The American species which may be referred to Spiriferina are few. The 

 Spirifer solidirostris. White, of the Kinderhook group, is a septate- lam ellose shell, 

 but the specimens we have examined do not evince punctation. Spiriferina 

 spinosa, Norwood and Pratten, and iS. transversa, McChesney, of the Chester 

 (Kaskaskia) limestone, S. subelliptica, McChesney, of the Keokuk group ; S. Ken- 

 tuckiensis, Shumard, and var. propatula, Swallow, and S. spinosa, var. campestris, 

 White, of the Coal Measures, are characteristic representatives. The forms which 

 have been described as S. Billingsi, Shumard, S. hinacuta and S. Clarksvillensis, 

 Winchell, and S. suhtexta, White, have not come under our observation. It 

 should be remarked that Walcott has regarded f /S Kentuckensis and var. propa- 

 tula, and S. spinosa as synonyms of Spiriferina cristata (Schlotheim), Davidson. 



Genus AMBOCCELIA, Hall. 1860. 



PLATE XXXrx. 



1842. Ortlds, Conrad. Journal Acad. Nat. Sci. Philadelphia, vol. viii, p. 264. 



1843. OHMs, Hall. Geology of N. Y. ; Kept. Fourth Dist., p. 180, fig. 8 ; p. 267, fig. 5. 

 1846. Orthis, Rouaclt. Bull. Soc. Geul. de France, sec. sev., vol. iv, p. 322, pi. iii, tig. 8. 

 1857. OHMs, Hall. Tenth Kept. N. Y. State Cab. Nat. Hist., p. 167, figs. 1-3. 



1860. Amboccelia.llAhh. Thirteenth Rept. N.Y. State Cab. Nat. Hist., p. 71, figs. l-3;p. 72, figs. 4-6; p. 81. 



1862. Ambocmlia (Spirifer f). White. Proc. Boston Soc. Nat. Hist., vol. ix, p. 26. 



1864. Amboccelia, Meek and Hattden. Palaeontology of the Upper Missouri, p. 20, 



1867. Amhoccelia, Hall. Pala;ontology of N. Y., vol. iv, pp. 258-262, pi. xliv, figs. 1-25. 



1883. Amhoccelia, Claypole. Proc American Philosophical Society, vol. xxi, p. 232. 



1887. Amboccelia, (Ehlbrt. Bull, de la Soc. d'Etudes Scientif. d'Angers, p. 6, pi. v. figs. 11-16. 



1889. Amboccelia, Nettelhoth. Kentucky Fossil Shells, pp. 85, 86, pi. xvii, fige. 25, 26. 



Diagnosis. Shells small, concavo-, or plano-convex. Marginal outline nearly 

 semicircular. Hinge-line long and straight, its length nearly or quite equaling 

 the greatest transverse diameter of the shell. 



* Devonian Brachiopoda, pp. 46, 48, pi. iv, figs. 11-17. 

 t Paleontology of the Eureka District, p. 218. 1884. 



