90 University of Texas Bulletin 



ceras Waageni Gemm.^ but' in this latter species the transversal ribs 

 are much more numerous, the spiral ribs are finer, and the umbilicus 

 is wider. 



The transversal ribs in our species are rather similar to those of G. 

 Jossae Vern.^ but the spiral costae are much finer in this species. 



From our G. roadense n. sp., the present species is easily to be dis- 

 tinguished by its wider umbilicus, the longer transversal ribs and the 

 smaller number of spiral costae. 



Age : 



Leonard formation, Permo-Carboniferous. The horizon is not ab- 

 solutely certain. The species was found by Dr. J. A. Udden. Judg- 

 ing from the rock, it comes from the Leonard formation. The second 

 specimen, collected also by Udden, probably comes from a place about 

 three miles south of Bird's Mine, in the Altuda Mountain region; at 

 least, it was kept together with fossils from the Leonard formation 

 of that place. 



Number of specimens examined : 



Two. According to Dr. Udden the species is rather frequent at one 

 of the localities, but most of the specimens were poorly preserved. 



Locality: 



About two miles southwest of Altuda station ( Southern Pacific Rail- 

 way), South of Bird's mine near the instrusive plug on Capt. James's 

 ranch. 



Gastrioceras sp. nov. indet. 

 PI. in. Fig. 7-8 

 Shell discoidal, very evolute, compressed on the flanks, rounded on 

 the ventral region; cross-section parabolical, greatest width a little 

 above the umbilical border ; whorl very little broader than high. Um- 

 bilicus very wide and shallow, no umbilical shoulder developed, the 

 flank curving down to the umbilical wall which is narrow and not well 

 limited. No constrictions are visible on the shell of the fragment, the 

 cast being unknown. 



'Gemmellaro, Calc. c. Fusullna, app. p. 25, pi. D. fig. 24-26. 

 'Verneuil, G6ol. de la Russie, II, p. 370, pi. 26, fig. 2 a-c (not fig. 3). 



