144 PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. [DoC. 20, 



favour of the conclusion that they were brackish-water or fresh- 

 water shells, allied to Mytilidce or to embryonic Unionidce. 



16. JSpirorhis carhonarius. — This little sheU, which I described as 

 a S^irorhis as long ago as 1845*, is apparently not specifically distinct 

 from Microconchus carhonarius of the British coal-fields. Its micro- 

 scopic structure^is identical with that of modern Sjpirorhes, and shows 

 that it is a true worm-shell. It is found throughout the Coal- 

 formation, attached to plants and to shells of Naiadites, and must 

 have been an inhabitant of enclosed lagoons and estuaries. Its 

 occurrence on Sigillarice has been used as an argument in favour of 

 the opinion that these trees grew in sea- water ; but, unfortunately 

 for that conclusion, the Sjnroo^bis is often found on the inside of Sigil- 

 Zfxrm-bark, showing that this had become dead and hollow. Beside 

 this, the same kind of evidence would prove that Lepidodendra, Cor- 

 daites, and Ferns were marine plants. Spirorles multiply fast and 

 grow very rapidly ; and these little shells no doubt took immediate 

 possession of submerged vegetation, just as their modern allies cover 

 fronds of Laminaria and Fucus. 



As I have not met with a description of this little shell, I may 

 state that it is dextral, with 2| to 3 turns. It is attached through- 

 out its length, and when not compressed presents a somewhat deep 

 umbilicus. It is closely marked with beaded or unequal transverse 

 ridges. It has when young a close resemblance to Sp. caperatus, 

 M!'Coy, from the Carboniferous Limestone of Ireland ; but this species 

 has only two turns, and is sinistral. 



17. Crustacea. — It appears in the table above that as many as four- 

 teen beds of coal exhibit in their roofs shells of minute Entomostraca 

 of the genera Cythere and Bairdia ; and these occur in such quan- 

 tities that considerable beds of shale and bituminous limestone are 

 filled with their valves. Professor Jones regards the species as 

 marine or brackish-water ; and the same remark will, I presume, 

 apply to the crustacean Biplostylus Dawsoni, and a fragment of 

 Eurypierus described by Mr. Salter from Coal no. 8 of Division 4 

 of the Section. Of the small Entomostracans there are several 

 species, which Professor Jones has now in his hands for determina- 

 tion. No Estherians have yet been found in the Coal-formation of 

 Nova Scotia ; but I have specimens of Leaia Leidyi from the Lower 

 Carboniferous of Plaister Cove, and an undetermined Estheria from 

 the same horizon at Horton Bluif. 



It is to be observed that Naiadites, Spirorbis, and Cythere con- 

 stantly occur associated in the same beds ; and the conclusions as to 

 habitat applicable to any one of these genera must apply to all. 



18. Fishes. — Remains of fishes occur in connexion with eighteen 

 of the coal-beds at the Joggins, usually in the roof-shales, though 

 detached scales, teeth, spines, or coprolites are of occasional though 

 rare occurrence in the coal itself, especially where the latter passes 

 into coarse coal or carbonaceous shale. One thin bed, no. 6 of 

 Division 4 of the Section, is full of remains of small fishes. It is 

 hard and laminated, and roofed with a calcareous bed full of remains 



•'^ Quart. Journ. Geol. Soc. vol. i. p. 326. 



