DEVONIAN SPBOIES. 33 



Greatest transverse diameter of corallum, 4 inches or more ; diameter 

 of mm^al circles, about 0.10 inch ; number of vesicular dissepiments seen 

 between two of the septa, in a space of 0.10 inch of vertical section, 8. 



It is possible that a very critical comparison of good specimens might 

 show some differences in the details of structure by which this coral could 

 be separated from the European SmitJiia Hennahii; but I have failed to de- 

 tect any characters, either mentioned in the descriptions or illustrated in the 

 most reliable published figures of that species, by which our specimens can 

 be distinguished. Every word in Edwards and Haime's description of S. 

 Hennahii, as they restrict the species, would apply equally well to the spec- 

 imens under consideration, so far as their structure can be made out. 



Locality and position. — Babylon Hill, White Pine Mining District, from 

 the silver-bearing rock ; Devonian. 



Genus CYATHOPHYLLUM, Goldfuss. 

 Cyathophyllum Palmeri, Meek. 



Plate 2, fig. 2. 



Corallum composite, astreiform, growing in irregular masses three to 

 four or more inches in diameter, with the corallites radiating in all direc- 

 tions from near the base of attachment. Corallites very unequal in size, and 

 usually pentagonal or hexagonal in form, with rather deep calices in the 

 middle; separated by nearly straight, moderately-projecting walls, excepting 

 where a young corallite protrudes a little beyond the others, when it is 

 sometimes surrounded by a nearly circular wall. Gemmation both calicu- 

 lar and interstitial; in the former case, the young corallites often growing up 

 directly in the middle of the calices of the old, and soon expanding so as to take 

 the place of the latter. Septa twenty-eight to thirty-four, well developed, 

 slightly denticulated, thicker, and most prominent for about half-way inward, 

 where every alternate one thins off to nothing, while the others continue on very 

 thin to the center, where they form, without twisting, a small projection in 

 the bottom of each calice. Vesicular dissepiments very thin, rather closely 

 aiTanged, and not continued in farther than the ends of the shorter septa. 



Breadth of the whole corallum, 4 or more inches; height, about '2.50 

 3p R 



