TISSOTIID ®. 5d 
the overlapping of the last sutures. These have low, broad, entire saddles 
and broad lobes, very different from any observed in that genus. The 
younger sutures resemble those of Tissotia more nearly than those of 
Sphenodiscus, the saddles being phylliform and entire. The ventral lobes as 
figured are quite different from those of any described species, so far as I 
know. How much of these peculiarities can be attributed to the metamor- 
phoses of age remains unknown, but these ventral lobes have apparently no 
siphonal saddles except a minute point that seems to be becoming obsolete. 
Unluckily this important point is not mentioned in the description. 
Locality: Bir Oum-el-Djof. 
Age: Campanian. 
TIssOTIA GLOBOSA n. sp. Hyatt. 
Tissotia thomasi Peron (pars), 1890, Moll. Crét. de la Tunisie, pl. 16, figs. 5, 6 (not 
pl. 13, fig. 3). 
This fossil, figured on pl. 16 by Peron, has a globose form with distinct 
proportions from the type of thomas, and the umbilical shoulders are quite 
prominent. The sutures also are distinct according to the figure given. 
The aspect indicates aftinity with Metatissotia rather than Paratissotia. 
Locality: North Africa. 
Age: Senonian. 
HETEROTISSOTIA Peron. 
If the type of this genus had been abraded so as to round off the venter, 
its sutures would have placed it near Tissotia, if not in the same genus. 
Nevertheless the flattened venter with keel, and the bifurcated, fold-like 
coste ending in slight tubercles on the edges of the smooth ventral zone and 
gathered into a few large nodes on the prominent umbilical shoulders are 
similar to those of several species usually included in Pulchellia. The 
affinities of this fossil appear to be indeterminable without some knowledge 
of the young. 
HETEROTISSOTIA NEOCERATITES Peron. 
Heterotissotia neoceratites Peron, 1897, Mém.. Soc. géol. France, Paléontologie, 
Vol. VII, No. 17, pl. 16, figs. 9, 10. 
Sufficiently described above, except that it is an involute compressed 
form with flat lateral zones and small but not very small umbilicus. The 
