21-1 University of Texas Bulletin 



of Vascoceras Douvillei; 3. Group of Vascoceras harttiiforme; 4. Group 

 of Vascoceras subconciliatum. 



Pervinquiere 1 unites the first two groups in one and distinguishes only 

 three subdivisions. This seems to me to be the best solution, as the divi- 

 sion of the first two groups appears to be rather artificial. 



Among the material of Cerro del Macho we find forms representing the 

 three groups. To the first one (in the sense of Pervinquiere) belongs our 

 Vascoceras aff. Gamai Choffat and Vascoceras aff. adonense; to the second 

 one Vascoceras Angermanni sp. nov., and perhaps Vascoceras aff. arnesense 

 Choffat; to the third one Vascoceras mohovanense n. sp. 



The genus Vascoceras so far has been found in Portugal, Spain, Algeria, 

 Tunis, Egypt, the Sahara, Nigeria, Brazil, Peru, and Mexico. 



VASCOCERAS sp. nov. ex aff. V. ADONENSE Choffat 

 PL 14, fig. 4; PL 17, fig. 2 



1886: Vascoceras adonense Choffat, Especes nouv. ou peu conn., p. 59, pi. 9, fig. 3; 

 pi. 21, fig. 12. 



Our specimen shows the following features: 



Internal mold rather large, a little oblique on account of deformation, 

 quite evolute, with whorls of a transversally semi-lunar cross-section, 

 much broader than high. The umbilicus is wide, the umbilical wall is 

 quite abrupt, the umbilical border is rounded and scarcely subangular. In 

 the external whorl no nodules exist on the umbilical border; the internal 

 whorls are not visible. The surface of the species is smooth, no orna- 

 mentation can be distinguished. 



The suture is very simple ; it is not very well preserved but the general 

 features can be well distinguished. The external lobe is quite wide and 

 not very deep and ends in two branches; the external saddle is wide at 

 the base, becoming narrower upward, and is very little ramified; the 

 first lateral lobe is funnel shaped, very wide at the mouth ; the first lateral 

 saddle is similar to the external one but smaller and inclined toward the 

 umbilicus while the external one rather bends over toward the venter; 

 the second lateral lobe is funnel shaped, very wide at the mouth and much 

 shallower than the first one; the second lateral saddle (on the umbilical 

 border) is similar to the first one but smaller. 



The dimensions could not be measured exactly on account of the de- 

 formation of the specimen. 



Pervinquiere, Paleontologie Tunisienne, p. 331. 



