2o6 University of Texas Bulletin 



The external saddle is twice as high as the median one, rather 

 slender, and rounded at the end. The first lateral saddle is similar 

 in form to the external one, but stouter and shorter. The second 

 lateral saddle is only half visible, of more triangular form. 



The internal lobes are very simple. They consist, between the anti- 

 siphonal line of symmetry and the umbilical seam, of two lobes, one 

 saddle and the larger half of the second lateral saddle of the external 

 suture. The anti-siphonal lobe is lanceolate, very long and narrow, 

 ending in a long and sharp point; the internal saddle is very high, 

 slender and a little, inclined toward the anti-siphonal lobe. The^ first 

 lateral lobe is much shorter than the anti-siphonal, and slightly asym- 

 metrical, the anti-siphonal flank being steeper than the umbilical one. 

 The next saddle is considerably lower than the first one and much 

 broader, the internal flank being much steeper than the one on the 

 other side of the umbilical seam. Unfortunately, this part is not quite 

 easy to recognize, but there does not seem to be room for doubt that 

 there is only one very broad saddle between the internal saddle and the 

 first lateral saddle on the external part of the suture. 



This species represents a rather uncommon form of Gastrioceras. I 

 do not refer to the sculpture or the involution, but to the suture. Gen- 

 erally, Gastrioceras shows between the sipho and the external border, 

 only the siphonal and one lateral lobe, while in our species we observe 

 two lateral lobes. The first lateral saddle is commonly very low and 

 diflferent in shape from the external one, while in our species it is 

 nearly identical, in its form. The general outline of our external su- 

 ture resembles more that of Paralegoceras than that of Gastrioceras. 

 Evidently we have a similar case to that of G. russiense Zwetaev where 

 the second lateral (or suspensive lobe) also lies on the flank. But the 

 number of lobes and saddles as well as the sculpture shows that our 

 species undoubtedly belong to Gastrioceras. 



On account of the deficient preservation of the sculpture and the 

 exceptional form of the suture, no comparison can be made with species 

 from other localities. 



Conclusions. 



The new faunas discussed here allow us to draw some conclusions 

 with respect to the difiFerent horizons of ammonoids in the Permo- 



