336 0ABBONTFEROU9 FORMATIONS A.N0 FAUNAS OF COLORADO. 



1890. Stenopora iuberculala. Ulrich, Geol. Surv. IlliiidiM, Kept., vol. 8, p. 441, fig. 17. 



Cliestcr group: Chester, 111. 



St. Louis limeatone and Warsaw beds. 

 1895. Stenopora tuberculata. Keyes, Missouri Geol. Surv., vol. .5, ji. l."). (Date of imprint 1894.) 



St. Louis limestone: Barrett Station, Mo. 



Kaska.skia limestone: Chester, 111. 



This form is represented by two excellent specimens. They agree very closely 

 with Ulrich's description of Prout's species, and although the latter is especially abun- 

 dant in and characteristic of rocks of the Genevieve epoch, and the present mate- 

 rial seems to be of Upper Carboniferous age, thej^ probably can safely be referred 

 to the same species. 



Locality and horizon. — Crested Butte district (station 2312); Weber limestone. 



Stenopora ? sp. 



Associated with the form which I have distinguished under the title of Leio- 

 clmna f sp. occur two other zoaria of a general appearance closely similar, but which 

 are probably at least generically distinct. ■ 



The shape of the zoarium is discoid, almost flat, more or less flexuous. Diame- 

 ter about 10 mm., thickness inconsiderable. Mesopores practically absent. Auto- 

 pores small, angular, 6 or 8 in a space of 2 mm. Walls thin. Acanthopores 

 probably present. Diaphragms probably absent. 



Though in general appearance similar to Leioclema f sp. with which this form 

 is associated, it can be distinguished without difiiculty by reason of its much smaller 

 cells and practical absence of mesopores. 



Locality and horizon. — San Juan region (station 2221"): upper portion of the 

 Hermosa formation. 



LEIOCLEMA Ulrich, 1882. 

 Leioclema ? sp. 



At station 2221 in the San Juan region occurs in considerable abundance a form 

 of whose generic position I am much in doubt, but which I have placed provisionally 

 with Leioclema. The zoaria are small and extremely thin. The shape is that of a 

 disk, slightly depressed in the center and more or less flexuous. The diameter is 

 usually under 12 mm. and the thickness inappreciable. The cells are minute, sub- 

 circular or petaloid in shape, and separated by abundant mesopores, which have an 

 angular outline. They radiate in an almost horizontal position from the center of 

 the colony. Acanthopores seem to be absent, and the height of the zocecia is so 

 slight as to suggest that diaphragms also are lacking. Certainly none have been seen. 



Locality and horizon. — San Juan region (station 2221); upper portion of the 

 Hermosa formation. 



