bCUL'CllEKTITES. 49 



Since this genus is so widely spread and so characteristic of the 

 Permian, this horizon lias been called the zone of Medlicottia. Closely 

 related species have been found in the same horizon and in approximately 

 the same association in the Artinsk formation of the Ural j\Iountains; in 

 the IVoductus limestone of the Salt Range of India; in the Fusulina 

 limestone >f Sicily; and in the Wichita formation of northern Texas. 

 Haug" has ttempted to subdivide the Permian into zones, based on species 

 of McdUcottia, but this is impracticable, since these species are not inter- 

 regional in distribution and since the exact stratigraphic relations of these 

 beds in various parts of the world are not yet known. 



Family NORlTIDxE. 

 Genus ScmiCHERTiTES o-en. nov. 



Form discoidal, laterally compressed; sides flattened; abdomen narrow, 

 angular, and channeled. Close coiled, involute, with narrow umbilicus. 

 Surface devoid of ribs, constrictions, and other ornamentation, except 

 curved cross stride of growth, forming gentle undulations on the shell. 



Septa ammonitic and complex, with numerous lobes and saddles. 

 Siphonal lobe divided into two short lobes by a secondary siphonal saddle. 

 First lateral saddle divided by a short rounded indentation or adventitious 

 lobe; all the other saddles rouiulcd and entire. Lobes somewhat digitate 

 and club-shaped, constricted at tlie upper portion. The septa, instead of 

 running straight across the sides, are arranged in a backward-pointing curve, 

 parallel with the stria^ of growth. 



No similar Paleozoic genus has been described, so its systematic position 

 is somewhat doubtful, especiall}' since the young stages of the shell are 

 unknown. But the compressed, involute, discoidal form and the compli- 

 cation (if tlie septa suggest a relationship to Medlicottia, hence it is grouped 

 near that genus under the superfamily Prolecanitida", and doubtfully 

 referred to the Noritida. The shape of the whorl, the character of the 

 septa, and the surface of the shell remind one strongly of Ilanerites Mojsis- 

 ovics, of the Upper Trias, but Schuvhcrtites is much too complex to have 

 been the ancestor of that genus; it is probably only a case of parallelism, 

 in accelerated development from a kindred stock. 



"Etudea sur les Goniatites, p. 70. 

 MON XLII — 02 4- 



