A New Ammonite Fauna of the Lower Turonian of Mexico 217 



of plate 7 ; unfortunately no figure of the form viewed from the side has 

 been published. The juvenile specimen of figure 3 of plate 7, the lateral 

 view of which is given in figure 2 of plate 10 of Choffat is also similar. 

 The main difference exists probably in the smaller number of umbilical 

 nodules in our specimen and in the narrower cross-section, although this 

 latter feature changes with the age. 



In the juvenile specimens of Vascoceras Mundae the ribs are less numer- 

 ous and thicker. 



Vascoceras Gamai Choffat occurs in Portugal mainly in the lower and 

 middle Turonian of Choffat, both of which according to my opinion belong 

 to the Salmurian. 



Number of specimens: 1. 



Age: Lower Turonian (Salmurian), probably from the upper horizon. 



VASCOCERAS ANGERMANNI sp. nov. 

 PI. 16, figs. 1-4; PI. 17, fig. 1 



In the collection of Dr. Angermann as well as in that of Dr. Haarmann 

 we find a globose cephalopod which at the first view resembles completely a 

 Nautilus. In the collection of Angermann there is a small, quite well 

 preserved specimen, and in Mr. Haarmann's collection a much larger one, 

 but the features of both are the same. There are also a number of frag- 

 ments which probably should be united with this singular species. Its 

 features are : 



Shell large, globose, extremely involute, with whorls of semi-lunar cross- 

 section, much broader than high. The whorls cover the preceding ones 

 nearly entirely. The umbilicus is narrow and deep, the umbilical wall 

 abrupt, the umbilical border smooth and angular. The surface of the 

 shell is entirely smooth without any nodules or ribs. 



The suture is not very well preserved but its general features can be 

 well recognized. The external lobe is quite deep and moderately wide, 

 ending in two branches. The external saddle is moderately broad, quite 

 high, very little ramified ; the first lateral lobe is little ramified, broad, ends 

 in two points and is deeper than the external one ; the first lateral saddle 

 is broad and rounded, less high than the external saddle. The second lat- 

 eral lobe is probably similar to the first but less deep ; it is not entirely pre- 

 served. 



Dimensions of the smaller specimen : 



