Permo-Carboniferous Ammonoids of the Glass Mountains i6g 



Gemmelkfo does not make any remarks about the curious para- 

 bolical course of the suture of Cydolohus, which alone probably would 

 be sufficient to separate it generically from Waagenoceras, but his 

 reasoning is entirely justified. The difference in the external form 

 and the suture of the two genera are so great that one cannot even 

 think of uniting them. Waagenoceras certainly belongs to the same 

 subfamily as Cyclolobus, but the latter genus represents a much more 

 highly developed form, and is at least as similar to Joannites as to 

 Waagenoceras. It must be taken into account that the shape of the 

 siphonal lobe of Cyclolobus is somewhat imperfectly known, as has 

 been pointed out by Diener.^ Waagen apparently has reconstructed 

 the median saddle of the siphonal lobe in his figure of Cyclolobus Old- 

 liamP and the suture of the very nearly related Krafftoceras Diener^ 

 shows that the median saddle of the siphonal lobe of Cyclolobus is 

 possibly still much more different from that of Waagenoceras' than we 

 could suppose. 



Whatever be the shape of the median saddle, there is no doubt that 

 the branches of the siphonal lobe are much more subdivided than those 

 of Waagenoceras and that their shape is entirely different, as Gem- 

 mellaro has shown. The external saddle in Cyclolobus Oldhami is 

 curved with the convexity toward the siphonal region, while that of 

 Waagenoceras has the convexity on the umbilical side. The most 

 important feature is the paraboHcal curve followed by the suture be- 

 tween the sipho and the umbilicus, which is not only found in C. Old- 

 hami but atso in C. Kraffti Dien. and in C. persulcatus Rothpl. from 

 the Permian of the Island of Timor, and which has the greatest simil- 

 arity to the curvature of the suture in Joannites. Waagenoceras, on the 

 contrary, always shows a suture the curvature of which is part of a 

 circle, as has been pointed otit by Mojsisovics. Diener^ is certainly 

 right, when he says that "Cyclolobus is linked as closely to Joannites 

 Mojs. on the one hand as it is to Waagenoceras Gemm., on the other." 



Most of the authors seem to have accepted the genus Waagenoceras. 

 Haug^ considers it as belonging to his Joannitidae together with Cyclo- 



'Diener, Permian foss. Centr. Himalayas, p. 167. 

 ^Waagen, Productus limestone fossils, I, p. 24, pi. 1, fig. 9. 

 'Diener, Permian foss. Centr. Himalayas, p. 162, pi. 6, fig.9. 

 *Diener, loc. cit., p. 14. 

 "E. Haug, Les Amm. du Permian et du Trias., p. 394. 



