60 PRocEEDmrGs of the geological society. [Apr. 28, 



represents the strata, at about high-water mark, arranged as occupy- 

 ing the space due to their real thickness only. 



The Carboniferous rocks in this section present three great 

 natural groups : — 1, the Lower Carboniferous ; 2, the Mountain- 

 limestone ; and 3, the Upper Carboniferous, or the workable coal- 

 measures. 



From Anstruther, on the east, to beyond Pittenweem the se- 

 quence of strata is clear, exhibiting a magnificent series of the 

 Lower Carboniferous rocks (approximately 3800 feet thick), con- 

 sisting of freshwater or estuarine shales and sandstones, with a few 

 bands of limestone, one of which latter is of marine origin. The 

 comparative abundance of Sjphenopteris affinis characterizes the 

 upper portion of this inferior group ; and of Cydopteris, its lower 

 portion. The Burdiehouse limestone belongs to the upper portion ; 

 and, like the other calcareous bands, gets thinner eastwardly. The 

 Granton beds, on the contrary, appear to belong to the lower 

 portion. 



The lowest portion of this Lower Carboniferous series has Cydo- 

 pteris, Stigmaria, Carpolithes, and Oypridce. The marine band — an 

 argillaceous limestone, in the middle of the series — ^has EncriniteSy 

 Fenestella, Nucula tumida, N. attenuata, and Productus semireticu- 

 latus. The upper half of the series contains Sphenopteris affinis, 

 Cypridce in abundance, and Falceoniscus. 



The strata have a westward inclination, with a gradually in- 

 creasing angle of dip, which is still greater towards St. Monance, as 

 the section traverses the " Mountain-limestone " series. This con- 

 sists of sandstones and shales, with five or six beds of limestone — all 

 of marine origin, and may be altogether about 400 feet thick. The 

 lowest of these bands of limestone (at Ardross) contains Nucula 

 tumida, N. attenuata, Schizodus sulcatus, Ooniatites, Natica, JSer- 

 pulites, Holoptydiius Hibberti, Eurypterus (?), Gampsonyoc, Dithy- 

 rocaris. The next band (E of the section) and its accompanying 

 "bone-bed" contain Productus semireticulatus, Aviculopecten, Spiri- 

 fera duplicostata, Cochliodus, Ctenacanthus, Pterichthys (?), and Eu- 

 rypterus. 



The fossils of the four limestone-bands (D, C, B, A) in the upper 

 part of the " Mountain-limestone" are Zaphrentis, Orthis filaria, 

 Productus punctatus, P. semireticulatus, Aviculopecten, Modiola, 

 Loxonema rugifera, Orthoceras, and Nautilus subsulcatus. 



This " Mountain-limestone" series passes under the Coal-basin 

 (Upper Carboniferous) of St. Monance*, reappearing with a re- 

 versed dip. Between St. Monance and Elie the strata are asso- 

 ciated with much trap-rock, and are singularly contorted: and 

 an important fault runs parallel with the coast, causing much con- 

 fusion. At Elie the beds have a westerly dip, and pass under the 

 great central coal-basin of Eifef- This consists of upper carboni- 

 ferous rocks, estimated by Mr. Laudale at 1700 feet in thickness. 



* See Mr. Laudale's description, Transact. Highland Soc. vol. xi. 

 t Including the coal-fields of Dysart, Weniyss, Leven, Largo, and Earlsferry. 

 See Mr. Laudale's Memoir in the Transact. Highland Soc. vol. xi. 



