196 



SYNOPSIS OF THE CHARACTERS OF THE 



MiLLEPORA EHOMBIFERA. Phil. 

 MLllepora rhombifera. Phil. Geol. York. 



Sp. Ch. — Cylindrical; surface with equal, rliomboidal cells, arranged in quincunx. 



This pretty species is not uncommon ; it is easily known by its round section, and rather large, acute, rliom- 

 boidal cells. Length usually from one to two inches, diameter three-fourths of a line. 



MiXLEPORA SIMILIS. Phil. 

 Millepora similis. Phil. Pal. Fos. 



Sp. Ch. — Stem oval, elongate, flexuous, dichotomous ; surface with numerous rows of close, rliomboidal 

 pores in quincunx. 



This species is very closely allied to the M. rhombifera, Phil. ; from which, however, it is easily distin- 

 guished by its much superior size, and its flexuous, depressed, dichotomous stem. 



Millepora (Pustulopora) spicularis. Phil. 



Millepora Spicularis. Phil. Geol. York. 



Sp. Ch. — Stem slender, round, branched; branches short, simj)le, terminating in fine points; surface with 

 rows of prominent, oval, unequal cells. 



This elegant little species is distinguished from its congeners by its numerous short, spicular branches. Its 

 stem is much smaller than in any of the other mountain limestone species. 



Tragos. Schweig. 



Gen. Ch. — Halycondroid ; skeleton simple, spicular; form capitate, attached by a root or bundle of fibres 

 expanding to a disc, with distant, unequal ostiolse, 



Tragos semicirculare. M'Coy. (PI. XXVII. fig. 8). 



Sp. Ch. — Pedicle semicylindrical, surmounted by a semicircular, flattened head ; ostiola on the upper sur- 

 face large, scattered, with a channel from each to the convex margin ; truncated margin furnished, with several 

 short processes. 



This fossil is so totally difi^erent in character from any other zoophyte wliich I know, that I am still uncer- 

 tain to what exact group it should be referred ; it appears, however, to belong to the family SpongiadcE, but not 

 to any of those divisions having interlaced fibres ; the genus Tragos is, in my mind, most nearly allied to it, 

 although the pedicle being at the margin instead of in the centre, and the numerous root-like processes to the 

 truncated margin, point out differences in habit worthy of generic distinction. Greatest diameter one inch, least 

 diameter six lines. Only two specimens have occurred. 



GoRGONiA. Linn. 



Gen. Ch. — Axis corneous, with osseous spiculse ; polypiferous basis cretaceous ; polypi developed ; cells ses- 

 sile, with simple or spinose margins. 



Gorgonla. assimilis. Lonsd. 



Gorgonia assimilis. Lonsd. SO. Syst. 



Some specimens refenible to this obscure species have occurred ; the general size, form, and occasional 

 anastomozing of the branches are the only characters visible. 



rj 



, \ 



-il 



