Permo-Carhoniferous Ammonoids of the Glass. Mountains 125 



scribed by Diener^, but this species must be regarded as belonging to 

 an entirely different genus, as it shows only three lateral saddles and 

 a median saddle which is much higher than the external one.^ We can 

 therefore leave it out of consideration. 



The shape of the siphonal lobe of Adrianites is extremely charac- 

 teristic, but this circumstance seems to have escaped most of the 

 authors. Karpinsky only refers to the difference between the median 

 saddles of the siphonal lobe but overlooks entirely the fact that how- 

 ever the form of this saddle may change, the two branches of the si- 

 phonal lobe are always narrow and curved, while in Agathiceras they 

 are of nearly the .same form and size as the first lateral lobe. Karpinsky 

 (loc. cit., p. 85) says that Adrianites isomorphus Gemmellaro (loc. cit. 

 app., pi. B, fig. 7) has the median saddle characteristic of Agathiceras, 

 while Agathiceras anceps Gemmellaro (loc. cit., pi. 7, fig. 22) has a 

 median saddle like that of the typical Adrianites. By comparing' in 

 these cases the form of the siphonal lobe we find that A. isomorphus has 

 the typical siphonal lobe of Adrianites, the branches of which are nar- 

 row and strongly curved, while A. anceps has the typical siphonal lobe 

 of Agathiceras, the branches being of about the same size and shape as 

 the first lateral lobe and not curved at all. Karpinsky also says that 

 Adrianites ensifer Gemmellaro (loc. cit., pi. VI, fig. 11-13; pi. VII, fig. 

 25) which has only four lateral lobes, should be compared with Agathi- 

 ceras Suessi Gemmellaro (loc. cit., pi. VI, fig. 1-4; pi. VII, fig. 36) ; 

 but this comparison proves once more the absolute reliance we can put 

 in the form of the branches of the siphonal lobe. A. ensifer has only 

 four lateral lobes and therefore is more similar to Agathiceras than 

 any other species, but the branches of the siphonal lobe are strongly 

 curved, while in Ag. Suessi they are broad and straight and oi the 

 same figure as the first lateral lobe. 



In our discussion of the genus we have already shown that Adrian- 

 ites cannot under any circumstances be united with Agathiceras on ac- 

 count of the different aperture and internal suture. But we had to 

 be somewhat prolix here with regard to those characters that allow us 

 to distinguish both genera, even where the aperture is not preserved 



'Diener, Perm. Foss. of the Central Himalayas, p. 117, pi. 5, fig. 26. 



'Dlener's figure 26-c has heen erroneously printed in a reversed position, as is 

 shown by the description of the author, but not noted in either the text or thi 

 explanation of the plate. 



