48 University of Texas Bulletin 



pecially of our Leonard beds (zone of Perrinites) seems to have very 

 intimate relations with that of the lower and middle Productus lime- 

 stone. Especially characteristic seems to be the frequency of the 

 group of Productus sino-indicus Freeh, represented by extremely 

 large individuals, as well as of the group of Productus gratiosus and 

 of Rhipidomella corallina Waagen sp. ; which, with the exception of 

 the second one, do not seem to be well represented in the European 

 Permo-carboniferous of the Alps and Sicily. Significant to a certain 

 degree is also the frequent occurrence of a Camarophoria very similar 

 to C. mutahilis Tschern., of the Schwagerina limestone of the Ural. 

 Not less important is the existence of numerous specimens of Lyt- 

 tonia, Oldhamina, and Pichthofenia, the latter one being much more 

 similar to those of India than those of Sicily, as has been shown in 

 another publication. 



Thus there is no doubt about a direct marine communication with 

 the Asiatic Permo-Carboniferous sea; but again, we do not know in 

 which direction and at what place the channel existed, little or nothing 

 being published abovit the Permo-Carboniferous strata west of the 

 Trans-Pecos region, especially in Arizona and California; although 

 a direct communication through these two states and New Mexico, 

 with Asia, seems to be extremely probable. 



Thus it seems that there existed an uninterrupted marine com- 

 munication between Europe and Asia through the actual American 

 continent during the Permo-Carboniferous, at least at the time of the 

 zone of Waagenoceras, and probably also during the zone of Per- 

 rinites. The brachiopod fauna, however, seems to be more nearly 

 related to that of Asia than to the European fauna, while the principal 

 ammonoid genus Perrinites is not known anywhere else than in Texas. 



I am not able to give more than a few slight indications with respect 

 to marine communications between the Trans-Pecos sea and those of 

 Asia and Europe, because ammonoids are rather scarce in most parts 

 of the earth during the Permo-Carboniferous ; but a study of the com- 

 plete fauna of the Glass Mountains will certainly show much more 

 clearly how more or less intimate are the relations between it and tne 

 other faunas of the same age known in different parts of the world. 



