BELLEROPHON. 
327 
spire seem to be hidden, at least on one side of this specimen, by a thickening of 
the lateral margin of the mouth. In the casts of the shell, however, the spire is 
well exposed on both sides. 
3. Bellerophon mundus, Whidhorne. PL XXXI, figs. 9, 9 a. 
1889. Belleeophon mundus, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 29. 
Description. — Shell small, globular, horizontally symmetrical, of few rapidly 
increasing whorls. Shell-structure very thick. Surface with a smooth, median, 
flattened area in place of a keel, and with low, close, rounded, very indefinite and 
discontinuous ridges arching forward from it on either side. Oast with a wide 
median groove bounded by rounded prominences about a quarter the width of the 
shell apart. Mouth reniform, much recurved and very wide, being nearly four 
times as wide as deep. 
Size. — Height of cast 13 mm., width 13 mm. 
Locality. — Lummaton. A single example is in Mr. Lee's Collection. 
Remarks. — This small specimen is almost entirely a cast. The surface can 
only be seen on a very small portion where the shell is retained ; and as that has 
been covered by an outer whorl, it may, perhaps, have partially lost its original 
character. The most remarkable feature of the species is the central depression 
seen upon the cast, which distinguishes it from almost every other species of 
Bellerophon with which I am acquainted. 
Affinities. — Bellerophon Lohestae,^ de Koninck, appears to have a much more 
indefinite central depression. B. excavatus, de Koninck,^ has a similar depression, 
but in the centre of it there exists a small median keel of which there is no sign 
in the English species. 
i 
4. Bellerophon macromphalus, F. A. Bomer. PI. XXXI, figs. 10, 10 a. 
1843. Bellekophon maceomphalus, F. A. Bomer. Verst. Harzgeb., p. 32, pi. ix, 
fig. 3. 
1884. — — Beushausen. Abhandl. Geol. Specialk. 
Preuss., Band vi, pt. 1, 
p. 44, pi. ii, fig. 1. 
1 1883, de Koninck, ' Ann. Mus. Eoy. H. N. Belg.,' vol. viii, pt. 4, p. 142, pi. xxxvi, figs. 7—9, 
and pi. xxxix, figs. 1 — 3. 
2 Ibid., p. 143, pi. xxxvii, figs. 6—8. 
