DESCRIPTIONS OF SPECIES. 99 



Locality. — Two aiid a lialf miles northeast of Clayton, Contra Costa 

 County, California. (Collected by T. W. Stanton.) 



Geologic occurrence. — Tejon group, above the coal horizon. 



Type. — United States National Museum. 



This species is founded upon one specimen embedded in an indurated, 

 coarse-grained, glauconitic sandstone. It Avas with great difficulty that 

 enough of the matrix was removed to permit as many details of the septa 

 and pali to be ascertained as are stated above. The base is eroded so that 

 the character of the costal ornamentation can not be described full)-. There 

 can scarcely be a doubt about the generic determination of the species, 

 notwithstanding our ignorance of some details. The other discoid species 

 of the genus are Tr. calif orniamis, Tr. ImmUtiformis, and Tr. depressits. Tr. 

 stantoni is the only one whose septa arch high above the corallum wall, and 

 the only one that has the base covered by epitheca. An examination and 

 com2)arison of the figures will make these differences appavent. The great 

 differences in the costae also will be readily recognized. 



Troohocyathus cingulatus sp. nov. - 

 PI. VII, figs. 19 to 19b. 



Form short cornute, basal portion small, subpedicellate, curved in plane 

 of lesser diameter of the calice. Transverse section subelliptical. Scar of 

 attachment preserved. Corallum wall ornamented by 42 low, distinct, gran- 

 ulate costse, corresponding to all cycles of septa, and alternating in size. 

 Epitheca appears to be entirely absent. There are several girdling depres- 

 sions and bands, giving the species a cingulate appearance. 



Septa are moderately strong, thicker near the wall, and sometimes 

 thicken somewhat before joining the columella, 42 in number; 21 principal 

 septa with alternating smaller ones. The various cycles are extremely 

 difficult to make out. Their sides are ornamented witli rather prominent 

 spines, which usually appear to be truncated. Columella fascicular. Greater 

 diameter of calice, 8.6 mm.; lesser diameter of calice, 8 mm.; height, 9.5 mm. 



Locality. — Prairie Creek, Wilcox County, Alabama. (L. C. Johnson, 

 collector.) 



Geologic occurrence. — In tlie lower Ijcds of tlic Cliickasawau stage, or in the 

 Midwayan stage. 



Type. — United States National Museum. 



This pretty little species is described fi-om a single specimen, Init it is 



