the Horton-Windsor District, N. S. 161 



of these stems with the ubiquitous drift of Lepido- 

 dendron corrugatum Dawson suggest the strong proba- 

 bility that the upright stems belong to this species. An 

 absence of horizontally spreading Stigmaria is in agree- 

 ment with the arenaceous character of the Horton soils 

 and absence of carbonaceous seams, which point rather to 

 good drainage and lack of permanent swampy conditions 

 before burial. 



Throughout the formation, broken plant material is 

 common. Larger recognizable fragments are almost ex- 

 clusively cortical imprints of Lepido dendron corrugatum 

 Dawson or of the broken foliage and rachises of the pteri- 

 dosperms Aneimites acudicus Dawson, two species repre- 

 sented by close allies in the American Pocono. In the 

 upper beds, large megaspores {Spongites glaher Dawson) 

 1-2 mm. in diameter are very abundant at certain horizons. 

 A single specimen of Astero catamites cf. scrohiculatus 

 Schlotheim was found as a stray fragment, presumably 

 from the upper Horton. 



In the restricted fauna the following ostracods are most 

 characteristic: Jonesina nova-scotica (Jones), a beyri- 

 chioid allied to Beyrichia colliculus Eichwald ; Kirhhyina 

 acadica n. sp., a larger and more quadrate form than K. 

 reticosa (Jones & Kirkby) ; K. cf. scot ohur dig alensis 

 (Jones & Kirkby) ; Carhonia cf . pungens Jones & Kirkby. 



The fish scales of most common occurrence are assigned 

 to the genus Elonichthys, differing from E. brownii (Jack- 

 son) from the Albert series of New Brunswick, in the 

 possession of nonserrate margins. Maxillae of Rhadi- 

 nichthys are not uncommon. Rarer remains are jaws 

 and teeth of Strepsodus, and selachian spines of the gen- 

 era Stethacanthus and Gtenacanthus. 



Depositional environment. — Marine conditions are ex- 

 cluded as inconsistent with a widespread extension of 

 rootlets and plant stems in situ, an exclusion corroborated 

 by the textural features of the deposits. General uni- 

 formity of deposition, carbon content, absence or rarity 

 of desiccation cracking, ferrous condition of the iron con- 

 tent, etc., testify to pluvial conditions. Among the pos- 

 sible terrestrial deposits, a fluviatile accumulation under 

 humid climatic conditions is postulated as most consis- 

 tent with all the facts. The laminated ostracod-bearing 

 shales may represent temporary lacustrine deposits on 

 the river plain. While the presence of the beyrichioid 



Am. Jour. Sci. — Fifth Series, Vol. I, No. 2.— February, 1921. 

 11 



