568 Notices of Memoirs — 



9. Favosites hemispherica, Tandell and Sbumard. 



10. Favosites Forbesi, Edw. and H. 

 B. Eamose species. 



a. With one row of mural pores, on the faces of the corallites. 



11. Favosites polymorpha, Goldf. 



12. Favosites cervicornis, De Blainville. 



13. Favosites reticulata, De Blainville. 



b. With one row of pores, placed in the angles formed by the 



prismatic faces of the corallites. 



14. Favosites fibrosa, Goldf. 



Of the above species, those which have been recognized as 

 occurring in the Devonian rocks of Canada are : Favosites GotJi- 

 landica, Lam. ; F. hemispherica, Yandell and Shumard ; F. Forbesi, 

 Edw. and H. ; F. turbinata, Billings; F. cervicornis, De Blainville; 

 and F. polymorpha, Goldf. 



I. Favosites Gothlandica, Lamarck. — "Corallum forming sphe- 

 roidal, pyriform, or large hemispheric or flattened masses ; corallites 

 are in general between one and one a half lines wide, sometimes more, 

 sometimes less, often two lines ; transverse diaphragms usually com- 

 plete, rarely incomplete; mural pores in one, two, or three series, 

 usually two, those of the same series about half a line distant, some- 

 times less ; pores surrounded by an elevated margin ; faces of the tubes 

 with one or two longitudinal striae, more or less distinctly developed ; 

 I'adiating septa represented by a series of small spines, often in the 

 rudimentary form of tubercles." — Billings. 



Whilst the above exist in typical specimens, there are numerous 

 departures from this state of things. The corallites are often uniformly 

 below the average in an entire colony, or nearly round instead of 

 polygonal. There is sometimes but one, and sometimes three rows 

 of mural pores. The tabulae are sometimes absent, and sometimes 

 form little projecting lamellas, or ridges, sometimes resembling those 

 of F. hemispherica, being closely set and incomplete, often more or 

 less bent, and commonly interlocking. 



The septa as a general rule are absent, or at any rate indetermin- 

 able, but are, however, not uncommonly to be recognized in the 

 form of small inequalities or minute tubercles. 



The shape of the colonies also varies much. The colony is based 

 on a concentrically wrinkled epitheca, which is very commonly 

 wanting in decorticular specimens, and attains a considerable thick- 

 ness in aged examples. 



Locality and Formation — Common throughout the Corniferous Lime- 

 stone in Canada West. 



IL Favosites basaltica, Goldfuss. — It is with regard to this species 

 that Prof. Nicholson is inclined to differ from the conclusions arrived 

 at by Mr. Billings. 



Making a single row of mural pores the distinguishing character 

 of this species, Goldfuss includes under this head — 



1. Specimens which differ only in this respect from F. Goth- 

 landica. 



2. Specimens which agree with the preceding in having some- 



