231) 



ACERVULARIA Scliwei.%'. 



ACERVULARIA DAVIDSONI Milne— Edwaids aud Haiiiie. 

 [Pal. Fo=8. des Terr. Pal. P. 4)8. PI. 9, Figs. 4-1 b (18-).]-' 



Coral composite, astra^iform and massive, composed of unequally sized, 

 usually live or six-sided corallites, having liotb an outer and an interior, 

 slightly undulated or zigzag wall. The outer wall is thin; the inner wall 

 is rarely well delined; the surface sinlvs, at first gradually and then 

 abruptly, to form the cup, the diameter of which is about one-fifth of an 

 inch. The bottom of the true calice is flat to slightly elevated. The 

 septfB are radially arranged, and are stout and finely denticulate, there 

 ))eing about seven denticulations in the space of one line. They are 

 usually about forty-two in number, and for the most part, extend into 

 the true calice. The tabular are abundant in the central area; the dis- 

 sepiments abundant in the periferal zone. The diameter of the larger 

 corallites is about one-half inch. 



This species -is most nearly allied to A. Profviifhi Hall, from which it 

 is distinguished by the larger size of the corallites, the greater constancy 

 in the size of the calices, the less niimber and less conspicuous denticula- 

 tion of the septa, and in the zigzag undulations of the outer walls. 



Range and Distribution.— Devonion formation, on the government trail, 

 four miles east of Canyon Creek, Arizona; on the John Dazen trail, three- 

 fourths mile southeast of the cliff houses near Oak Creek, and along the 

 rim of the Tonto basin. Arizona: at the falls of the Ohio and at Sandusky, 

 Ohio, etc. 



CERIOCRINUS? 

 Plate, Fig. 3. 



The specimens referred to this genus are a few detached plates and 

 are insutticient to fully identify even the genus. 



Position and Locality.— Upper Red Wall, north bank of White River 

 Canyon, twelve miles southwest of Fort Apache, Gila County, Arizona. 



ARCH.l^OCIDARIS McCoy. 



ARCH.EOCIDARIS. 



Plate, Fig. 7. 

 The specimens here called Areluvovidarls are some fragments. They are 

 too imperfect for identification of the species; but, though much worn, 

 are sufficient to identify the genus. 



"For a figure of the fossil here deaoribed the reader is referred to plate XXX of the 

 November number of the American Geologist for 1903. 



