314 Annals of the South African Museum. 



Family SCALAKIID^. 



Genus SCALA, Humphreys. 



ScALA OBNATA (Baily). 

 Plate XXXVIII., figs. 2, 3. 

 1855. Scalaria ornata, Baily, Q.J.G.S., xi., p. 459, pi. xii., fig. 2. 

 1871. Scalaria turbinata, Griesbach, Q.J.G.S., xxvii., p. 64 {non 

 Forbes). 



Description. — Shell elongate turbinate, imperforate, consisting of 

 ten or eleven convex, rounded whorls, with a rounded keel at the 

 periphery of the base. The posterior face of the keel is seen on the 

 whorls of the spire, but may be concealed by the overlap of the last 

 whorl. Spiral angle 27°. 



Whorls ornamented with sixteen stout, rounded, transverse ril^s, 

 which are nearly straight and slightly oblique to the axis of the shell. 

 The ribs are separated by broad, rounded interspaces, and both are 

 crossed by fine, rounded spiral ribs separated by linear grooves. At 

 intervals some of the spiral ribs are shghtly larger than the others ; 

 near the middle of the whorl three or four smaller ribs may be seen 

 between the larger ribs. The spiral ribs are crossed by very fine, 

 sharp, linear, parallel, transverse ridges. 



Affinities. — Griesbach thought that this species could be identified 

 with S. turbinata, Forbes," from the Ariyaliir Group, but it clearly 

 differs from that form by its smaller spiral angle, more elongate 

 spire, less convex whorls with the keel quite at the periphery ; also 

 the spiral ribs are placed more closely together. As was pointed out 

 by Stoliczka, *S'. ornata is allied to S. slmtanurcnsis, Stoliczka,! from 

 the Trichinopoli Group, but in the former the spiral ribs are much 

 finer and more uniform in size than in the latter. 



The European forms to which S. ornata shows resemblance are 

 S. decorata (Komer) | and S. Diqyiniana, d'Orbigny.i- Gardner || 



* Trans. Geol. Soc, ser. 2, vol. vii. (1846), p. 124, pi. xii., fig. 18. S. suhturbi- 

 nata, d'Orbigny, Prodr. de Pal., vol. ii., p. 217. Stoliczka, Cret. Fauna S. India, 

 vol. ii. (1868), p. 232, pi. xviii., figs. 2, 3. 



t Ibid., p. 233, pi. xviii., figs. 6-8. 



+ Verstein. nord-deutsch. Kreidegeb. (1841), p. 82, pi. xii., fig. 11. Geinitz, Das 

 Elbthalgeb. in Sachsen (Palfeontographica, vol. xx., 1874), pt. 2, p. 162, pi. xxix., 

 fig. 4. Holzapfel, Mollusk. Aachener Kreide (Palseontographica, vol. xxxiv., 1888), 

 p. 165, pi. xix., fig. 1. 



§ Pal. Fran(,'.. Terr. Cret., vol. ii. (1842), p. 54, pi. cliv., figs. 10-13. Gardner, 

 Geol. Mag. (1876), p. 100, pi. iv., figs. 5, 6. 



Il Ibid., p. 107. 



