100 PSEUDOCERATITES OF THE CRETACEOUS. 
CoILOPpocERAS? GROSSOUVREI n. sp. Hyatt. 
Pl. XII, fig. 7. 
Sphenodiscus requient Grossouvre, 1893, Ammonites Craie supérieure, p. 141, fig. 59. 
The suture and description given by Grossouvre of his French species 
and the one figured by d’Orbigny as Ammonites requienianus, although 
quoted as identical by him, are very different. There are distinctly three 
principal lateral saddles in Grossouvre’s figure, but the first is large, long, 
and trifid instead of being narrow, long, and bifid; the second is really an 
enlarged branch of the first saddle and still entire, while the third is bifid and 
much larger than in true requieni, according to d’Orbigny’s figure. This 
species may be one of the hollow-keeled group, a suggestion that is further 
supported by the aspect of the auxiliary saddles and lobes. In order to call 
attention to these points I have placed a question after the generic name. 
Locality: Near Tours, France. 
Age: Turonian. 
ACONECERAS* n. gen. Hyatt. 
The single species here referred to this genus has sutures more lke 
those of Cretaceous forms of Phylloceratida than any others of this group. 
These are combined with a highly volute compressed shell having an 
ax-like acute venter like a species of Hulophoceras. The ventral saddle, as 
figured by d’Orbigny, is broad and similar to that of Cotlopoceras; the first 
lateral and the other saddles are deeply divided and broader than in the 
Phylloceratida and certainly show approximation to those of the Coilopo- 
ceratidee. I have therefore referred the form to this family, and it appears 
to strengthen the opinion that the Coilopoceratidee were derived from the 
Phylloceratidee. 
ACONECERAS NisuM (d’Orbigny). 
Pl. XII, figs. 4-6. 
Ammonites nisus VOrbigny, 1840, Terr. Crétacé, pl. 55. 
This figure is copied from d’Orbigny because it gives what appears to 
be an important link in the evidence that the group to which it is referred 
is correctly referred to the Phylloceratida.’ 
Age: Neocomian. 
« Akovn, a whetstone. 
» The two pages of manuscript bearing these notes on Aconeceras were out of place, lying at the 
top of one of the two bundles of manuscript, and just before the generic name is the penciled note, 
