184 



rhomboidal, with entire margins. Stratum, Lias. Locality, Whitby. 

 Cab. Enniskillen. 



5. Pholidopliorus hartmanni, E2;erton. — Size of Pholidophoriis 

 latlusculus. Head rounded ; orbit large ; upper angle of operculum 

 striated ; preoperculum marked with few raoniliform inequalities ; 

 humerus plicated ; scales small, serrated on the posterior Eoargin ; 

 its sen-ations decrease in number and increase in size on the pos- 

 terior parts of the body. Stratum, Lias. Locality, Ohmden, in Wur- 

 temburg. Cab. Enniskillen, Egerton. 



6 Pholidophorus crenulatus, Egerton. — Rather larger than Pho- 

 lidophorus latiusculus. Head rather pointed ; humerus obliquely 

 plaited ; pectoral fins large, with 22 rays ; caudal fins strong ; the 

 upper lobe bordered full two-thirds of its length with fulcral scales ; 

 rays 28 — ^30 ; scales ribbed vertically on their bases, furrowed hori'-' 

 zontally on their exposed surface, and crenulated on the posterior mar- 

 gin ; the ventral scales deeply incised. Stratum, Lias. Locality, Lyme 

 Regis. Cab. Egerton. 



" On the Coal-formation of Nova Scotia, and on the age and rela- 

 tive position of the Gypsum and accompanying marine limestones.^"' 

 By Charles Lvell, Esq., F.G.S., &c. 



Tlie stratified rocks of Nova Scotia, more ancient than the car- 

 boniferous, consist chiefly of metamorphic clay-slate and quartzite, 

 their strike being nearly east and west. Towards their northern 

 limits these strata become less crystalline and contain fossils, some of 

 which Mr. Lyell identified with species of the upper Silurian group, 

 or with the Hamilton group of the New York geologists. 



The remaining fossiliferous rocks, so far as they are yet known, 

 belong to the carboniferous group, and occupy extensive tracts in 

 the northern part of the peninsula, resting unconformably on the pre- 

 ceding series. They may be divided into two principal formations, 

 one of which comprises the productive coat- measures, agi-eeing pre- 

 cisely with those of Europe in lithological and palseontological cha- 

 racter ; the other consists chiefly of red sandstone and red marl, 

 with subordinate beds of gypsum and marine limestone ; but this 

 series is also occasionally associated with coal grits, shales, and thin 

 seams of coal. 



A variety of opinions have been entertained respecting the true 

 age of the last mentioned, or gypsiferous formation ; and it is the 

 purport of this paper to show, first, that it belongs to the carboni- 

 ferous group ; secondly, that it occupies a lower position than the 

 productive coal-measures. These last are of vast thickness in Nova 

 Scotia, being largely developed in Cumberland county and near 

 Pictou, and recurring again at Sydney, in Cape Breton. In all these 

 places they contain shales, probably deposited in a freshwater 

 estuary, in which several species of Cypris and Modiola abound. 

 The plants of these coal-measures belong to the genera Calamites, 

 Stigmaria, Sigillaria, Lepidodendron, Pecopteris^ Neuropteris, 

 Sphenopteris, Nceggerathia, Palmacites, Sternbergia, Sphenophyl- 

 lum, AsterophyUites and Trigonocarpvm^ with which are the trunks 



