90 PSEUDOCERATITES OF THE CRETACEOUS. 
whether Ammonites heteropleurus Struckmann® and Amm. gevrilianus Dunker,’ 
which were found partly in the same localities in north Germany, are 
identical or not, but they are probably the same. 
Locality: Near Springe, Hanover. 
Age: Neocomian. ‘ 
PLATYLENTICERAS PSEUDOGRASIANUM (Uhlig). 
Oxynoticeras pseudograsianum Ublig, 1901, Denksch. K. Akad. Wiss., Wien, Vol. 
LXXII, p. 25, pl. 2. 
This is a really discoidal shell with a much larger umbilicus than other 
species of this genus, and therefore making a nearer approach to the radical 
form of Mojsisovicsia, but it has on the other hand the characteristic sutures 
of the P. heteropleurum type; that it should have a rounder venter until a 
late stage is quite consistent with its noninvolute discoidal aspect.’ 
Locality: Nieder-Lischna. 
Age: Valangian (Lower Neocomian). 
PLATYLENTICERAS GEVRILIANUM (d’Orbigny). 
Ammonites gevrilianus VOrbigny, 1840, Terr. Crétacé, pl. 43. 
This species was noted by Neumayr and Uhlig, in their Ammonitiden 
aus den Hilsbildungen, as having similar sutures and similar external char- 
acters to Platylenticeras heteropleurum, which is, however, in my opinion 
quite distinct. Aconeceras nisum was also cited by them as an ally, but this 
has only one principal first lateral and the resemblances exist only in the 
external characters. Amm. marcousanus, also cited by them as an ally, has 
only one large bifid first lateral and has a depressed rounded volution and 
tubercles like Pachydiscus. 
Age: Aptian. 
aJahrb. K. preuss. geol. Landesanstalt, 1889, p. 71, pl. 11, figs. 3, 4. 
»Paleontogr., Vol. I, 1851, p. 324, pl. 41, figs. 21-24. 
¢The other species mentioned and figured by Uhlig are not named. They are closer to the 
involute character of P. heteropleurwm, but one of these, Oxyn. cf. heteropleurum, pl. 2, fig. 2, has three 
principal saddles instead of two and is considerably less involute than that species. 
