Weno and Pawpaw Formations 107 



prominent), E. aguilerae Bose, Hemiaster elegans Shumard, H. whitei 

 Clark, H. sp. ( Fredericksburg division), H. calvini Clark. The antero- 

 lateral rows are conspicuous, consist of eight to nine cup-like elevations 

 decreasing in size outwards from the peristome, the cavities opening out- 

 wards and forwards in the anterior row, outwards and backwards in the 

 posterior row. Each cavity bears two nearly circular ambulacral pores, 

 placed obliquely. The antero-lateral and postero-lateral craters make two 

 V-shaped rows at their junctions back of the peristome. The postero- 

 lateral rows each contain about five similar, smaller craters which are 

 lower and more widely spaced farther from the peristome. 



Peristome oval, the long axis transverse, the anterior curvature being 

 even, the posterior margin with a central, bluntly rounded, elevated, for- 

 wardly projecting lip. 



Periproct rather similar to that of Epiaster aguilerae Bose: shape 

 trapezoid with the bottom and top rounded, the two superior angles being 

 sharply rounded and the superior margin but slightly arched; the sides 

 diverge, making the periproct broader at the bottom than at the top; 

 the inferior angles are broadly rounded and the inferior margin likewise, 

 it being nearly the arc of a circle of the same diameter as the periproct. 



RELATED SPECIES: Epiaster wenoensis n. sp. is smaller than 

 E. aguilerae Bose; is more narrowed and pointed posteriorly; is less ele- 

 vated medially just posterior to the apical system, but farther posteriorly 

 is more straight-topped, the slope to the periproct being relatively abrupt ; 

 the notch made in the ambitus by the anterior sulcus is shallower and less 

 pronounced than in E. aguilerae; the peristomal ambulacral pores are 

 larger and more pronounced, more numerous and more crowded than in 

 any other Texas species examined ; the species is more smooth in appear- 

 ance and more sparsely tuberculated aborally than E. aguilerae Bose or 

 H. elegans Shumard. 



The relations existing between Hemiaster, Epiaster and Macraster in 

 the Texas Comanchean have not been satisfactorily solved. Hill 1 and 

 Clark- have considered Macraster texanus Roemer 3 to be synonymous with 

 Hemiaster elegans Shumard. 4 Roemer and Bose 5 state that this species 

 comes from the Fredericksburg division, but Hill 6 says that| it "makes a 

 well defined horizon near the very top of the immense thickness of lower 



iHill, Annotated Check List, etc., Geol. Surv. Texas Bull. 4, p. 2, 1889. 



'Clark and Twitchell, U. S. G. S. Mon. LIV, p. 88, 1916. 



"Roemer, Neues Jahrb. f. Min., Geol. p. Pal., Bd. I, pp. 191-195. Tf. VI, 1888. 



'Shumard, Pal. Exp. Red River of La. in 1852, p. 210, pi. II, fig. 4a-c, 1853. 



5 B6se, Inst. Geol. Mex. Bol. 25, p. 173, 1910. 



"Hill, On the Occurrence of Macraster texanus, Amer. Nat., XXIII, p. 68, 1889. 



