44 ON THE SPECIES OF FAVOSITES OF TliE 



of F. hasaltica, differ from one another in their characters to such 

 an extent that they would usually be (as they actually have been) 

 separated into two distinct species. On the one hand, making the 

 existence of a single row of mural pores the distinguishing character 

 of the species, Goldfuss includes under this head forms which differ 

 only in this character from F. Gothlandica ; and, on the other hand, 

 he associates with these other forms which difier very widely from 

 F. Gothlandica in most of their characters, but which are believed to 

 agree with the preceding in the above-mentioned feature. We may, 

 therefore, consider that the F. hasaltica of Goldfuss was made origi- 

 nally to include the following two groups of specimens : — 



1. Specimens agreeing with F. Gothlandica., Lam. in possessing 

 prismatic corallites, the size of which is upon the whole generally 

 uniform, but which differ from F. Gothlandica in possessing but a 

 single row of mural pores [Petref. PI. xxvi. figs. 4 c, 4 d~). 



2. Specimens which agree with the preceding in having sometimes 

 (not always) a single row of pores, but which differ in having nearly 

 rounded or cylindrical corallites, the sizes of which are exceedingly 

 unequal ; whilst the place of complete tabulae is taken by numerous 

 short projecting lamellae, which impart a peculiar and characteristic 

 appearance to the inner surface of the corallites {Petref. PL xxvi. 

 figs. 4 «, 4 h). 



NoAv, it is. the first of these groups of specimens that palaeontolo- 

 gists have generally agreed in regarding as the type-form of F. hasal- 

 tica, Grold. ; and the chief difference of opinion has simply concerned 

 the question whether these forms are separable from F. Gothlandica, 

 Lam., or not. Some authorities, such as McCoy and Lonsdale, main- 

 tain, apparently with good reason, that these forms are truly referable 

 to F. Gothlandica ; whilst others, such as Milne Edwards and Haime, 

 retain these forms tinder a separate species, under the name of F. 

 hasaltica. Whichever of these views may be ultimately adopted, I, 

 at any rate, have seen no specimens from the Corniferoiis Limestone 

 of Western Ontario which appear to me to be truly referable to the 

 type here alluded to. We do meet, certainly, with specimens exhibit- 

 ing prismatic basaltiform tubes, in every respect resembling F. Gothlan- 

 dica, except that the corallites are on the average a little smaller, and 

 that they exhibit but a single row of mural pores. These specimens 

 I was at first sight disposed to set down as belonging to F. hasaltica, 

 and I have seen them so named by others. I have, however, sue- 



