DEVONIAN SPECIES. 29 



rather arcuate, or sometimes nearly straiglit along most of their length, 

 every alternate one (or sometimes more) extending in nearly or quite to 

 the middle, where they become tortuous, and apparently form a small, false 

 columella ; transverse plates stout, sometimes dividing, sloping a little from 

 near the fossula to their free margins, which are subcrenate, while within 

 they curve abruptly downward around the fossula, Transverse sections 

 showing what appear to be a few dissepiments, arching strongly outward 

 between the septa ; but these may be oblique sections of the divisions of 

 the infundebuliform plates. Vertical section showing a small prominence 

 at the bottom of the central fossula, and under the fossula a few thin dis- 

 sepiments passing transversely or curving a little upward as they approach 

 what appears like a slender central columella. 



Breadth, nearly two inches ; height, somewhat less than one inch. 



The specimens of this coral in the collection are very imperfect, and 

 leave some doubts in regard to its true relations. Possibly I should call it 

 Chonophyllum infimdibulum, to which genus I was at first inclined to refer it. 

 On making vertical sections of one of the specimens, however, I have found 

 some appearances of a small, false columella. If these appearances are not 

 deceptive, it would fall into the genus Ptycliophyllmn ; but, if there was no 

 columella, it would have to be referred to the genus ChonophjUum. Its 

 septa, however, are much less numerous than those of any of the described 

 species of the former genus ; while it has also a smaller number than in 

 any of the latter known to me, and likewise has a differently-formed 

 calice. 



Locality and position. — Treasure Hill, White Pine Mining District, 

 Nevada ; from the silver-bearing Devonian rocks of that region. 



Genus DIPHYPHYLLUM, Lonsdale. 



DiPHYPHYLLUM FASCICULUM, Meek. 



Plate 2, figs. 4, 4 a, 4 6. 



Corallum growing in tufts ; corallites slender, elongated, cylindrical, 

 moderately flexuous, and often adhenng or growing together where brought 

 into contact by the flexures, or sometimes by short, irregular, transverse 

 processes; gemmation lateral; epitheca thin, and easily removed by weatli- 



