CYCLOLOBINAE Zittel 



Perrinites nov. g'cii. 

 Type : Perrinites vidriensis Bose 



There has been described from the Texas Permo-Carboniferous at 

 least one, but probably two, species under the generic name of Waag- 

 enoceras which certainly do not belong to this genus. One of these is 

 Waagenoceras HUH Smith-* and the other Waagenoceras Cumminsi 

 White.^ Waagen,^ Freeh,* and Diener,^ have considered this latter 

 species as belonging to Hyattoceras; and Smith acknowledged that 

 the septa of his Waagenoceras Hilli more resemble those of Hyatto- 

 ceras than of Waagenoceras, but he thought that it should be rather 

 considered as belonging to this latter genus, because Hyattoceras has 

 a closed umbilicus. 



There is no doubt that the shape and suture place the two Texan 

 species in the vicinity of Hyattoceras and Waagenoceras, but the very 

 circumstance that some authors consider them to belong to one genus 

 and others to the other, shows that there must be some difference of 

 importance. 



Before we discuss the difference between the Texas forms and those 

 of Sicily, we must first make clear the difiference betwen Waagenoceras 

 and Hyattoceras. With respect to shape Waagenoceras is generally 

 subglobose, while Hyattoceras is more'discoidal; the first genus is 

 involute but shows an open umbilicus, while the second one has a 

 closed umbilicus. These dififerences, of course, would not be sufficient 

 to separate both groups generically. The principal difference exists 

 in the form of the sutures. In Hyattoceras, the suture follows a 

 straight line, while in Waagenoceras it is strongly curved between 

 the sipho and the umbilicus. In the first genus the saddles in general 

 are broad at the base and taper upward, while in the. second one, they 

 are extremely narrow at the base and become rather narrower than 



'J. p. Smith, Carb. Amm. of North America, p. 140, pi. 27. 



=Ch. A. White, The Texan Permian, p. 20, pi. 1, fig. 4-8. 



•W. Waagen; Productus limestone fossils. Geological results, p. 203. 



*Fr. Freeh, Lethaea geognostica; die Dyas, p. 512. 



"Diener, Permian fossils of the Central Himalayas, p. 115. 



