Per mo-Carboniferous Ammonoids of the Glass Mountains 137 



shallower and narrower than the others while the next one is very nar- 

 row and funnel-shaped. 



The median saddle of the siphonal lobe is slightly notched by a 

 shallow indentation and constricted near the base. The external and 

 the two lateral saddles are very similar to each other, the external one 

 being the highest, the others gradually decreasing in height. The first 

 auxiliary saddle is a little broader than the preceding ones ; the second 

 auxiliary saddle, near and on the umbilical shoulder, is very broad 

 and much lower than the other, and is not constricted at its base. 



The internal suture (pi. VI, fig. 79, 80) is very characteristic. It 

 consists of an antisiphonal lobe divided in three parts by two slender 

 and long saddles. The middle branch is lanceolate, symmetrical, end- 

 ing in a rather sharp point. It is much deeper than the two lateral 

 branches; these are asymmetrical, ending in a point which is near 

 the inner side of the branch. The two saddles which divide the anti- 

 siphonal lobe are long and slender, rounded, somewhat constricted 

 above their base, and leaning a little toward the median branch lobe. 

 The first lateral lobe is much narrower than the antisiphonal one, but 

 broader than either of its branches. It is asymmetric and bifid, the 

 outer point (on the umbilical side) being longer than the inner one. 

 The second lateral lobe is asymmetrical and trifid, the middle point be- 

 ing the deepest, while the outer one is shorter than the inner one. This 

 lobe is somewhat broader and less deep than the first one. The first 

 auxiliary lobe is again asymmetrical and bifid, the inner point being a 

 little longer than the outer one. This lobe is nearly as broad as the 

 first lateral lobe and a little deeper than the second one. The second 

 auxiliary lateral lobe is nearly symmetrical and bifid, both prongs be- 

 ing about the same length. The internal saddles are all high, slender, 

 rounded, and slightly constricted at their base. The internal saddle is 

 the highest, the first and second lateral are of equal height, but a little 

 lower than the internal saddle ; the first auxiliary is broader and a little 

 lower than either of the others. A second auxiliary saddle exists on 

 both sides of the umbilical seam. It is somewhat asymmetrical, of 

 pyramidal form and slightly notched by a shallow indentation of its 

 upper part. 



