52 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



Niagara formation. — Head of Lake Temiscaming, Que. Sir Win. E. 

 Logan; north end of Lake Temiscaming Que. Dr. R. Bell. 1887. 



Syringopora retifoemis, Billing.s. 

 Plate II., fig. 3. 



Syringopora retiformis, Billings. 1858. Rep. of Progress for 1857, Geol. Survey of 



Canada, p. 170. 



Nicholson. 1874. Palseon. of Ont. p. 58. 

 Syringopora tenella, Rominger. 1876. Geol. Sur. Mich., Foss. Corals, p. 80. pi. 30, fig. 4. 



" Forming large masses ; corallites much geniculated, frequently anas- 

 tomosing or connecting by stout processes ; diameter of corallites about 

 two-thirds of a line, distant from each other from half-a-line to a line and 

 a half ; distance of connecting processeas one line to three lines, usually 

 about two lines." 



In this species, as in some others of the genus, the corallites show a cer- 

 tain variation in the regularity of their growth, especially in the basal 

 portion of a corallum ; instead of the corallites being in a general way 

 parallel to each other they are sometimes lax in their mode of growth, a 

 result probably due to disturbing influences during the life of the coral. 

 This laxity of growth is apparent in a specimen from Owen Sound, Ont., 

 which bears a striking resemblence to S. tenella, Rominger, as figured on 

 plate XXX. of the Fossil Corals of Michigan. One of the principal char- 

 acteristics of <S^. tenella, from the Niagara of Point Detour, Michigan and 

 Drummond Island, Lake Huron, is the coming together of the corallites 

 without the intervention of connecting tubes, a feature particularly 

 noticeable in the above mentioned example of S. retiformis from Owen 

 Sound. In other examples of aS'. retiformis, in which there is a more 

 general parallelism of the corallites, it is difficult frequently to determine 

 whether there are short connecting tubes present, or whether the coral- 

 lites are in juxtaposition, at the geniculations. The corallites in S. reti- 

 formis are described as being " much geniculated, frequently anastomosing 

 or connecting by stout processes." Judging from Dr. Rominger's des- 

 cription and figure the writer is led to believe that S. tenella, Rominger, 

 is the same as a!)\ retiformis, Billings. It may be well to state that the 

 Niagara rocks extend in an apparently unbroken line from Point Detour 

 and Drummond Island eastward to Owen Sound. 



Niagara group. — Isthmus Bay, Lake Huron. A Murray ; lot 13, con- 

 cession 7, Derby township, county of Gray, R. Bell ; Owen Sound, Ont., 

 J. Townsend, 1882. 



