52 CONTRIBUTIONS TO CANADIAN PAUEOKTOLOGY. 



Niagara formation. — Head of Lake Temiscaming, <l u< '- Sir Wm. El 

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



Btbiitoopo&a BETIFOBMIS, I »ill i i 



Plate II., fig. 3. 



Byringopora retiformitf Billing!. L868. Rep. of ProgreM for 1 sr>7, Geol. Survey of 



Canada, p. 170. 



Nicholson. 1874. Palnon. of Ont. p. 58. 

 Syringopora tcnc/hi, Etominger. 1H70. GeoL Sur. Mioh., Pot p. Oorali, p. 80. pi. 80, 1 



11 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-aline to a line and 

 a half ; distance of connecting processess 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 j instead of the corallites being in a general way 

 parallel to each other thefy 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 8. 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 8. retiformis from Owen 

 Sound. In other examples of iS. 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 8, tenella, Rominger, 

 is the same as *b\ retiformis, Billings. It may bo 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. 



