On the Senonian Ammonite Fauna of Pondoland. 
137 
specimen C 19461 is nearer to the (at a corresponding size) slightly less 
closely costate and more evolute example figured by Woods. In this last 
specimen (C 19461) the costation is regular, single, and relatively closer on 
the inner whorls ; in the first (C 19441) the beginning is more distantly 
costate, and closeness of the ribbing and bifurcation set in only at a later 
stage. 
A still more closely costate type than C 19461 is C 19442, but here the 
sharp umbilical edge of the holotype is lost on the outer whorls. The suture- 
line of this example is figured on Plate VII, fig. 4. C 19454 has a more 
distantly costate beginning even than C 19441, but otherwise is a character- 
istic M. soutoni. Specimen C 19451, on the other hand, in which the distant 
costation of the inner whorls persists to a comparatively late stage, and 
which also has a more inflated outer whorl, is transitional to M. aff. umkwel- 
anense, Crick, described by the writer.* Still another and more evolute 
form (C 19460) has the costation of the outer whorl more distinctly reclined 
than the holotype or other examples. Finally, No. C 19447, similar in the 
inner whorls to the example figured by Woods, has costation simple on the 
outer whorl and more distant than the ribbing of any other specimen. 
The Zululand form described by the writer as M. aff. soutoni is not 
represented in the present collection. 
34. Mortoniceras stangeri, Baily sp. 
(Plate IX, fig. 2.) 
1921. Spath, loc. cit. (Zululand), p. 297. 
1921. „ „ (Pondoland), table to p. 50. 
Thirty-one examples, including a few impressions and plaster-casts 
thereof, are referable to this species and its varieties, the great majority 
of the examples being close to the specimen figured by Woods and to Baily's 
holotype (Geol. Soc. Coll., 11366) and two paratypes (11367 and 68). They 
include specimens C 19440 and C 19443, the suture-lines of which were 
figured in text-figs, lc, lb of the writer's Zululand paper (p. 297), and 
C 19459, of which a sectional outline of the inner whorls and the internal 
suture-line were given (loc. cit., pi. xxiii, figs. 3a, b). 
The dimensions of Baily's types are : — 
Holotype (11366). Paratype (11367). Paratype (11368). 
Diameter . . . 320 mm. 101 mm. 115 mm. 
Height of outer whorl . 26 per cent. 31 per cent. 27 per cent. 
Thickness of outer whorl 19 „ 31 ,, 27 ,, 
Umbilicus ... 56 „ 47 „ 51 „ 
* Loc. cit. (Zululand, 1921), p. 234, text-fig. D 2, p. 297. 
