TISSOTIUD. 51 
PARATISSOTIA FICHEUR1 (Grossouvre). 
Tissotia fichewri Grossouvre, 1893, Ammonites Craie supérieure, p. 35, fig. 17. 
Tissotia jicheuri Peron, 1897, Mém. Soc. géol. France, Paléontologie, Vol. VII, 
No. 1%, pl. 12, figs. 1, 2; pl: 18, fio. 2. 
Buchiceras ewaldi (pars) Peron, 1890, Moll. Crét. de la Tunisie, pl. 15, figs. 3-6. 
Buchiceras fourneli (pars) Bayle, 1878, Expl. de la Carte géol. France, Vol. IV, pl. 
40, figs. 2 and 4 (not fig. 3). 
This is a very much compressed shell, with no channels on either side 
and no tubercles on the costae, which are simple and very slightly 
developed. The keel is prominent and acute, and the umbilicus is very 
small. The costee are shown by Peron in the side views of a young 
specimen having a diameter of 55 mm. and in a very old shell with 
diameter exceeding 115 mm. In both the coste are linear and straight, 
with only the outer half developed. A description of this last specimen, 
which is evidently very old, would have been of much interest, but it is 
not given. The very broad, low denticulated saddle occupying the 
extremity of the ventral lobe and the deeply divided denticulated first 
lateral saddles of this species, of which the outer one is bifid and the inner 
has a broad, phyllitorm base, are very peculiar, as are also the costae. The 
very globose fossil figured on pl. 15, fig. 8, by Peron in his Mollusques 
Crétacés de la Tunisie as part of his Buchiceras ewaldi 1s undoubtedly a 
distinet species, but the information given is too limited to enable one to 
refer it to any known species. The reference of part of B. fourneli Bayle 
to this species is given on the authority of Grossouvre. Bayle’s figures 
are handsome, but not very instructive. 
Locality: North Africa. 
Age: Base of Senonian. 
PARATISSOTIA SERRATA (Hyatt). 
Pl. II, figs. 7-11. 
Buchiceras serratum (pars) Hyatt, 1875, Proc. Boston Soc. Nat. Hist., Vol. XVII, 
p- 370. 
This is a fragmentary cast of more than one-half of an entire coil, without 
living chamber. The diameter without the shell is 37 mm. The outer 
volution measures 20 mm. at larger end, the umbilicus 4 mm., and opposite 
