170 The Ottawa Naturalist. [October 



NOTES ON A STROMATOPOROID FROM THE HUDSON 

 RIVER FORMATION OF ONTARIO. 



By Lawrence M. Lambe, F. G. S. 



Labechia Huronensis, Billing-s, sp. 

 Stenopora HuroJiensis, Billing-s, 1865. Pal. Fossils, vol. 1, p. 185. 



Tetradhim Huj-onejise, Foord (in parte). 1883. Contr. to Can. 

 Cambro-Sil, micro-pal., p. 25, pi. vii, figs, i, la. 



Labechia ohioensis, Nicholson, 1885, Mon. Brit. Strom, p. 32, 

 footnote and pi. 11, figs, i and 2. 



Labechia 7)1011 fifera, Ulrich. 1886. Contr. to Am. Pal., vol. i, 

 p. 33, pi. II, figs. 9, 9a. 



Labechia ohioensis, Nicholson, 1886. Ann. and Mag. Nat. Hist. 

 P- 13- 



There are in the Museum of the Geological Survey a number 

 of specimens of a Labechia, from Cape Smyth, Lake Huron, 

 collected by Doctor R. Bell in 1859. These specimens were de- 

 scribed by Mr. Billings in 1865 in the Palaeozoic Fossils, vol. i, 

 under the name Stenopora Huronensis. 



In one of his papers in the "Contributions to Canadian Cam- 

 bro-Silurian Micro-palajontology," Mr. A. H. Foord states that 

 having made a microscopical examination oi Steiwpora Huroiietisis, 

 Bill., he finds that it belongs to the genus Tetradium. Mr. Foord 

 gives an amended description of this species as he understands it, 

 but unfortunately includes in it two distinct forms, under the 

 name Tetradium Huronense. The specimens represented on plate 

 VII, fig. I, of Foord's paper consists of a Zrt'<5>£'c/z/Vz, the minute 

 structure of which is well preserved, incrusting- a small mass of 

 Tetraditim fibratjim, Saff"ord. The original of figure la is a 

 small portion only of a large mass of the Labechia measuring 

 nearly 5 i^ inches across. These specimes figured by Foord were 

 those used by Billing-s in describing Stenopora Huronensis and are 

 still in the museum of the Survey. The structure is clearly shown 

 on polished surfaces in both specimens proving beyond doubt that 



