SYNECHODUS. 221 



Horizons and Localities. — Zone of Holaster subglobos as : Soiitheram, near Lewes, 

 Sussex ; Dorking, and near Guildford, Surrey. Zone of Scldoenbachia Darlaits : 

 Dover, Kent. 



4. Synechodus recurvus (Trautschold). Plate XL VI, fig. 8. 



1877. Sjihenodtis recurvus, H. Tfaufscliokl, Bull. Sue. Imjj. Nat. Moscou, vol. lii, p. 335, pi. v, fig. 4. 

 1889. tiynechodus recurvus, A. S. Wootlward, Catal. Foss. Ksbes B. M., pt. i, p. 329. 

 1889. Synechodus sp., A. S. Woodward, tuin. cit., p. 330, pi. xii, fig. 7. 



Type. — Tooth from Cenomanian of Saratov, Russia. 



Specific Gharactei's. — Somewhat larger than the type species and known only 

 by teeth. Main cusp high and compressed, Avith acute lateral edges, its flattened 

 outer face smooth or only a little wrinkled at the base, its convex inner face 

 marked only by a few fine vertical wrinkles at the base ; lateral cusps separately 

 inserted on the root, slender, sharply pointed, and marked with fine vertical 

 Avrinkles ; base-line of crown straight or gently arched; lower outer edge of root 

 coarsely crimped. 



Description of Specimens. — Two teeth from the Upper Chalk of Norwich in 

 the British Museum (Nat. Hist.) agree so closely with typical specimens of S. 

 recurvus from the Cenomanian of Russia that tXiey probably belong to the same 

 species. Both of them exhibit all the features noted in the above diagnosis, and 

 the best is represented in PI. XLVI, fig. 8. In this tooth the inner pair of 

 lateral denticles is relatively large, bent inwards, and slightly divergent. The 

 small outer lateral denticles are supplemented hj a minute point at their base. 

 The root is pierced by nutritive foramina, of Avliich the largest forms a small 

 postero-median cleft. 



Horizon and Localltij. — Zone of Beleuinltella inacronata : Norwich. 



Some detached teeth from the Upper Chalk of Norwich may perhaps belong 

 to other species of Sijuechodiis. One of these, presented to the British Museum 

 by Mr. B. B. Woodward (no. P. 584-6), closely resembles a tooth from the zone of 

 Beleninltella mncronata at Meudon, France, described by F. Priem, Bull. Soc. Greol. 

 France, [o] vol. xxv (1897), p. 48, pi. i, figs. 29 — 32. In several respects it 

 agrees with the anterior teeth of S. nltldns, but differs in being marked with a few 

 fine vertical ridges on the lateral denticles and on the inner face, while it lacks the 

 crimped border of the root which is so conspicuous beneath the outer face in the 

 teeth of the latter species. Its crown is excessively inclined inwards. 



The specimen in the Mantell Collection from the Chalk of Lewes named 

 Sfrophodvs asper by Agassiz (Poiss. Foss., vol. iii, 18o8, p. 128 h, pi. x h, figs. 

 1 — 3), is not a Cestracioiit tooth but a fragment of a Crustacean. 



