lambe. ] CANADIAN PALEOZOIC CORALS. 177 



sides and average about 3 mm. in breadth, forming masses evidently 

 of considerable size ; represented by two fragments, the largest of which 

 is 8 cent, high and 6 cent, broad. The corallites are somewhat irregularly 

 marked by decided transverse, often slightly oblique, growth ridges, and 

 are covered by an epitheca regularly striated longitudinally by septal fur- 

 rows. Calyces not observed. Septa from eighteen to twenty-two in 

 number, alternately long and short, the former passing to the centre and 

 producing a slender columella, the latter extending only a short distance 

 inward from the wall. Frequently a primary septum instead of passing 

 to the centre joins the one next to it at a short distance from that point. 

 A narrow peripheral area formed of small upwardly and outwardly 

 arching plates in one or two cycles surrounds a broad tabulate inner zone. 

 Tabulae flat or slightly raised at the centre, where they are crossed by the 

 columella, about fifteen occurring in a space of 5 mm. 



" This species resembles Lithostrotion (Stylaxis) irregularis, McCoy, * 

 from the Carboniferous limestone of Derbyshire, but the corallites are 

 smaller, the septa are less numerous and there are fewer rows of vesicles." 

 (Lambe, 1899.) 



Locality. — Fossil Point, Peace River, British Columbia, two fragments 

 probably belonging to one specimen, collected by Professor J. Macoun in 

 1875 ; Lower Carboniferous. 



CHONOPHYLLID^]. 



Genus Omphyma, Rafinesque and Clifford. 1820. 



Omphyma, Rafinesque and Clifford. 1820. Ann. des Sci. Phys. de Bruxelles vol. 5. 



p. 234. 

 ? Ptychophyllum, Milne- Ed wards and Haime. 1850. Brit. Foss. Corals, p. lxix. 



11 Single conical polyp cells of cyathophylloid structure, composed of 

 invaginated calycinal cups, the bottoms of which have the form of spacious 

 diaphragms, either smooth or crested by the radial lamellse uniting in the 

 centre. The ascending side walls of the cups are encircled by linear, 

 crest-like plications, which connect into uninterrupted vertical laminae, 

 within this intermediate area. At the peripheral cup margins the plica- 

 tions become tent-shaped, embracing one another in their superposition, 

 but not always combining with their edges into uninterrupted vertical 

 leaves. The interlamellar interstices are traversed by transverse plates, 

 and divided into cellulose spaces, but the dissepiments are not independent 

 vesiculose leaflets ; they make part of the tent-shaped folds of the invagi- 

 nated series of cell cups, and represent the rounded, outwardly directed 

 flexion of the plicated cup walls, while the inwardly turned folds are 



* Brit. Palaeoz. Fossils, 1855, p. 101, pi. 3a, fig. 5. 

 L— 6 



