L*«6E- ] CANADIAN PALAEOZOIC CORALS, 87 



lites, but in other respects it agrees with the description of Rjminger's 

 species, which is characterized as follows :— " i'lat, undose expansions of 

 laminated structure. Tubes one millimeter wide, orifices not projecting, 

 crenulated by twelve marginal crests. Diaphragms slightly convex. In- 

 terstitial spaces usually larger than one tube diameter, their surface deli- 

 cately reticulated by circumscribed cell spaces, as in Heliolites, but in 

 vertical sections exhibiting a distinctly interlacing vesiculose structure, 

 and not a tubular coenenchym. Found in the Niagara group of Point 

 Detour and Drummond Island (Lake Huron)." 



This species differs from Lyella exigua, Billings, only in having larger 

 corallites with larger intercalicular areas. 



Lyellia supebba, Billings. (Sp.) 

 Plate v., figs. 4, 5 and 5a. 

 Trematopora superba, Billings. 1866. Cat. Sil. Foss. of Anticosti, p. 93. 



Corallum forming fiabellate or flattened narrow expansions with lobes 

 or branches lying in the same plane, and with calyces on both sides as 

 well as on the rounded edges. The corallum attains a breadth in the 

 fiabellate forms of 8 or 9 cent with a thickness of from 5 to 10 mm. 

 Corallites circular, from -iQ to about -6 mm. in diameter and at a distance 

 from each other generally greater than their width, but varying from -5 to 

 1'5 mm. The corallites proceed outward from the central axial part and 

 emerge at right angles to the surface, the circular margins of the calyces 

 being slightly exsert. The spaces between the corallites are filled with 

 vesicles of rather unequal size, varying from -25 to 75 mm. wide, those 

 in the inner part being somewhat larger than those near the surface, 

 making the structure near the surface more compact. Tabulse are present 

 in the corallites ; they are horizontal, regularly disposed, about four occur- 

 ring in a distance of 1 mm. Septa of the usual number, twelve, but little 

 developed. The type specimen is 13 cent, high, broken at both ends, 

 elliptical in transverse section, about 2 cent, broad throughout its length 

 and about 8 mm. thick, with lobate outgrowths proceeding at an obtuse 

 angle from the main part of the corallum. 



A very strong resemblance exists between Heliolites Orayi, Milne- 

 Edwards and Haime, judging from their description and figures, and 

 Lyellia superba, Billings. The former species was described as follows* 

 " Corallum composite, dendroidal, forming lamellar sublobated expansions, 

 both surfaces of which bear calices. These are placed at various distances 



* Monograph of the British Fossil Corals, Milne-Edwards and Haime, 1850-1854, p. 

 252, pi. LVIII., figs. 1, la. 



