54 CONTEIBUTIONS TO CANADIAN PALEONTOLOGY. 



Guelph formation. — Durham, Ont. J. Townsend, 1883. 



Mr. Whiteaves has recorded the occurrence of this species at New Hope 

 (now called Hespeler), E. Billings, 1857 : Elora, David Boyle: as well as 

 at Durham, J. Townsend, 1883. 



Syeingopoba compacta, Billings. 



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

 Canada, p. 169. 



" Forming large hemispherical masses of straight parallel or slightly- 

 diverging corallites, which are so closely aggregated as to compose a nearly 

 solid mass ; about six corallites in two lines. 



" This species differs from all others of this genus hitherto described in 

 the closeness of the corallites. These are so small, straight and closely 

 united that large masses broken in the longitudinal direction of the tubes 

 have the aspect of some species of Monticulipora." (Billings.) 



In Syringopora compacta the corallites are seldom more than "33 mm. 

 apart and often at frequent intervals they are contiguous. The connect- 

 ing tubes are necessarily very short, and, when the corallites touch each 

 other, they are replaced by circular openings like the pores of Favosites. 

 The average diameter of the corallites is about -66 mm. The corallites 

 seen in longitudinal section present the usual deeply depressed or irregu- 

 larly funnel-shaped diaphragms distinctive of the genus. 



Lower Helderberg formation. — L'Anse a la Vieille, Que. Sir Wm. E. 

 Logan. 1843. 



Syringopora Maclurei, Billings. 



Syrinr/opora mbiporoides, Billings. 1858. Rep. of Progress for 1857, Geol. Survey of 

 Canada, p. 171. 

 " ii Billings. 1859. Canadian Journal, new series, vol. IV., p. 116, 



%. 17. 

 Aulopora cornuta, Billings. 1859. Ibid. vol. IV., p. 118, fig. 20. 

 Syringopora Maclurei. Billings. 1860. Ibid. vol. V., p. 258. 



IT M Billings. 1863. Geology of Canada, p. 366, fig. 366. 



« 11 Nicholson. 1874. Paljeon. of Ont., p. 41, 



" 11 Nicholson. 1875. Geol. Surv. of Ohio, vol. II. , p. 241. 



H M Rominger. 1876. Geol. Sur. Mich., Foss. Corals, p. 82, pi. 



XXXI., figs. 1, 2 and 3. 



" This species is found in large masses of long slightly flexuous corallites. 

 These have a diameter of about one line and a half, and owing to their 

 flexuosity, are at times in contact, and often two, three or four lines apart. 

 In large colonies which have grown luxuriantly without the interference 

 of disturbing causes, the corallites are more regular than in the smaller or 



