Permo-Carboniferous Ammonoids of the Glass Mountains 41 



Aganides sp. ind. 

 Nomismoceras Smithi n. sp 



Most of these ammonoids show a very characteristic and well de- 

 veloped sculpture but extremely simple sutures, with the exception of 

 the so called Hyattoceras aff. Cumminsi. This interesting form ap- 

 parently belongs to a genus related to Hyattoceras, but certainly has 

 nothing to do with Perrinites Cumminsi. I have compared a specimen 

 of Perrinites vidriensis of about the same size as the Hyattoceras aff. 

 Cumminsi Diener and I have been able to state that the character of 

 the suture is very different. In Perrinites the saddles are stout, of 

 pyramidal form, with shallow secondary lobes; and they end in a 

 broad, rounded leaf like those of the large specimens, only that the'phyl- 

 loid end is relatively much broader. The saddles of Hyattoceras Cum- 

 minsi Diener are much more slender and the incision deeper, and there 

 does not exist the well rounded terminal phyllum. While Perrinites 

 shows even in the younger stages a very high median saddle which 

 divides the siphonal lobe into two parts, the Indian species has a very 

 low median saddle in the rather shallow siphonal lobe. The Indian 

 form differs also generically from Hyattoceras by its rather evolute 

 form, the smaller number of saddles, and lobes, and the less phylloidal 

 terminals of the saddles. But it has to be taken into consideration that 

 Diener's shell is very small and that one cannot quite know the final 

 form of the suture. It seerhs that the genus belongs to the Cyclolo- 

 binae and that its position is nearer the less developed forms {Perrin- 

 ites, Hyattoceras) than the higher ones (Waagenoceras, Cyclolobus) . 

 The occurrence of this form may indicate that the Productus shales of 

 Lilinthi correspond more or less to our zone of Perrinites, or to some 

 part of the Sosio beds, but a real proof for this supposition does not 

 exist. 



The other ammonoids described from Lilinthi do not give any in- 

 dication of the age of those strata. I doubt very much that Diener's 

 Adrianites (Hofmannia) sp. has really anything to do with Hofman- 

 nia. The suture is entirely different on account of the enormously 

 high median saddle in the siphonal lobe and of the rather tongue- 

 shaped saddles; those of Adrianites showing always a distinct con- 

 striction above their base. 



