DEVONIAN ROCKS OP CANADA WEST. 109 



rougLnesa of the inner faces of tlie tubes of F. lasaltica above alluded 

 to, may be tbe eflect of some peculiar mode of fossilization, and 

 should not be relied upon as a specific character ; and I have seen 

 some fragments which appear to be portions of large dome- shaped 

 masses, that I could not distinguish from F. Gotlilandica on the one 

 hand, nor from the summit of a large specimen of F. hasaltica on the 

 other. 



Locality and formation. — Kama's farm, near Port Colborne ; near 

 "Woodstock ; lot 6, con. 1, "Wainfleet. 



Pavosites turbinata. — (Billings.) 



Corallum forming elongate turbinate masses, sometimes two feet 

 in length and six inches in diameter, often curved at the base. Coral- 

 lites nearly of an uniform size, usually somewhat less than a line in 

 width ; transverse diaphragms thin, flat, flexuous, complete or incom- 

 plete. Only one row of pores have been observed. Whole surface, 

 except the upper part, covered by a strong epitheca which closes the 

 mouths of the cells. 



The distinguishing peculiarities of this species are : 



1. The form of the colonies — which often resemble a huge, elon- 

 gated straight or curved CyathopTiyllum. Yery small ones about the 

 size and shape of Zaphrentis prolijica (see fig. 22, page 121) are not 

 uncommon, but they are found of all dimensions up to two feet in 

 length, and six inches in diameter. Some of them are straight and 

 very obtuse, or suddenly enlarging at the base, becoming cylindrical 

 above. 



2. The cells are all closed, except on the top of the colony. It 

 appears that the corallites had an average duration of vitality, at the 

 end of which the polyp died, and the epitheca extended itself over and 

 into the aperture, and completely closed it. In many specimens the 

 edges of the disc which fills the mouth of the cell, retains the impres- 

 sions of the radiating septal spines. 



The above two characters appear to me so remarkable that I think 

 this species new. 



JLocality and formation. — Rama's farm, near Port Colborne ; lot 19, 

 con. 3, "Walpole ; lot 30, con. 4, Cayuga. Corniferous limestone. 



