Handbook of Paleontology 375 



the State is the basal Devonian formation. The New- 

 Scotland limestone, with a thickness of approximately 

 75 to 100 feet, is the least conspicuous and most 

 fossiliferous member of the Helderbergian series. It 

 consists of thin-bedded, very impure, shaly limestones 

 and calcareous shales which tend to be heavier and less 

 fossiliferous, at least in certain areas as the Indian Lad- 

 der in the Helderbergs where in the lowest 20 feet or 

 so only the brachiopods Lingula and Orbiculoidea were 

 found and these sparingly. Locally seams of black chert 

 appear in the uppermost 20 feet or so. The middle beds 

 are, on the whole, the most fossiliferous. In fresh ex- 

 posures the rock has a dark bluish gray color and mas- 

 sive appearance and looks like a true limestone. When 

 weathered these beds have a gray or gray-brown color. 

 In general fossils occur in the New Scotland only as 

 impressions or natural molds but in certain areas where 

 the limestone is more silicious, the fossils have become 

 silicified. The New Scotland beds, were known in the 

 old days as the "Delthyris shaly limestone" because of 

 the common and characteristic brachiopods Spirifer 

 (Delthyris) perlamellosus and S. (Delthyris) macropleura 

 Brachiopods form a large and conspicuous part of the 

 New Scotland fauna and bryozoans are numerous. Next 

 in abundance to the brachiopods are the gastropods. Be- 

 sides the common Spirifers, among the brachiopods are 

 found Leptaena rhomb oidalis, Stropheodonta (Lepto- 

 strophia) becki, Strophonella headleyi, Eatonia medialis, 

 Ortho.strophia strophomenoides , Meristella laevis and M. 

 arcu-ata, Dahnanella perelegans and D. subcarinata. 

 Rhipidomella oblata and Camarotoechia acutiplicata. The 

 pelecypods are represented by Actinopteria communis 

 and A. textilis, Aviculopecten tenuilamellatus and 

 Pterinea halli; the gastropods by Diaphorostoma ventri- 



