DEVONIAN ROCKS OF CANADA WEST. 127 



sides of the septa striated witli from six to eight arched ridges in one 

 line, and their free edges denticulated with the same number of 

 minute spines. In the central area the transverse diaphragms are 

 well developed, and sometimes constitute a pseudo-collumella, which 

 exhibits itself in the shape of a small elevated boss in the centre of 

 the cup. 



This species is found in large densely aggregated masses, which 

 have much the external aspect of certain species of the genus Acervu- 

 laria, but with an internal structure identical with that of HeliopJiyl- 

 lum. It constituted a passage between the latter and PMllipsastrea, 

 the only difference between the two being that in the one the 

 corallites are either simple or partially connected laterally, while in the 

 other they are so intimately united that the septa of the contiguous 

 cells are confluent. 



Locality. — Eama's Farm, near Port Colborne. 



Genus Phillips astke a. — (Edwards and Haime). 



Generic Characters. — This genus, as above stated, does not differ 

 from Heliophyllum, except in having the corallites united laterally 

 throughout their whole length so that the septa of the contiguous cells 

 are confluent. 



Fig. 24. Phillipsastrea Verneuili. 



Phillipsastbea Veenetjili. — (Edwards and Haime). 



Phillipsasteea Veenetiilli. — Edwards and Haime, Polypiers 

 Fossiles, p. 446, pi. 10, fig. 5, 1851. 



This species forms large flat masses, with the surface covered with 

 stars about half an inch in diameter. The cup is usually three lines 

 wide, with a rounded margin from which the surface slopes in all 



