180 PALEOZOIC TIME. 



them species of Paradoxides (one, two feet long), Conocoryphe, Agnostus, Leperditia, 

 and Theca ; also, the Oldhamia antiqua, Fig. 27G, a species, probably vegetable, found 

 with 0. radiatu, Fig. 277, at Bray Head, in Wicklow, Ireland. 



From the Harlech grits have been obtained species of Paradoxides, Conocephalites 

 (Conocoryphe), Microdiscus, and Plutonia Sedgwickii, among Trilobites; a species of 

 Theca among Pteropods; and a number of kinds of worm -burrows ; also the Paheopyge 

 Bamsayi S., a supposed trilobite. 



In the Menevian beds have been found: Among Protozoans, Protospongia fene- 

 strata S. : among Mollusks, Theca corruyata S. ; among Trilobites, Pa rail oxides 

 Davidis S., P. Aurora S., Apopolenus (near Paradoxides) Henrici S., A. Salteri Hicks, 

 Conocoryphe (Conocephalites) variolar^ S., C. bufo, Hicks. C. (?) humerosa S., C. 

 applanata 8., Agnostus princeps S., Erynnis venulosa S., Microdiscus punctatus S.; 

 among Ostracoids, Leperditia Solvensis Jones, with other species of this group; 

 among Worms, at Bray Head, Histioderma Hibernicum Kinahan. 



The Lingula flags, as restricted, contain the Brachiopod Lingulella Davisii McCoy, 

 Fig. '278, Olenus micrurus S., Fig. 280, species of Conocoryphe, Dicellocephalus, etc., 

 Hymenocaris vermicauda, Salter, Fig. 282, etc. 



Some of the Bohemian Primordial species are: Agnostus Rex Barr., Fig. 279; A. 

 integer Barr., from Skrey, Paradoxides Bohemicus Barr., Sao hirsuta Barr, Fig. 281; 

 Elliptocephalas depressus S., Conocoryphe invito, S., C. striata Barr., some species of 

 Cystids. Bavarian serpentine, of Primordial age, has afforded Giimbel the Eozoon 

 Bavaricum. Sweden has afforded the British species, Paradoxides Hicksii S., besides 

 other fossils. 



No Polyp corals have been found in any Primordial beds. Over seventy species of 

 Primordial Trilobites have been discovered in Scandinavia, and nearly thirty in Bohe- 

 mia. The Eophyton Sandstone at Lugnas, in Sweden, which has been referred to the 

 Cambrian, and is of the " Fucoid region " of the Swedish geologists, has afforded a 

 Lingula, besides species of a genus of plants called Eophyton, which have been consid- 

 ered terrestrial plants, and are placed by Linnarson near the genus Bhachiopteris of 

 Dnger. The absence of the successors to these species in the later Lower Silurian 

 throws doubt on this reference of them. 



IV. General Observations. 



1. North American Geography. — On p. 149 a map is given, pur- 

 porting to represent the general outline of North America at the close 

 of the Archaean or during the earlier part of the Silurian. It is there 

 stated that there may have been other lands above the water, large and 

 small, in the great continental sea ; but that the continent, in a gen- 

 eral way already defined as to its ultimate outline, lay at no great 

 depth beneath the surface. The facts gathered from the rocks of the 

 Primordial era throw additional light on early American geography. 



The fact that the depositions of the Acadian period occur only on 

 the border of the continent — along eastern Newfoundland, New 

 Brunswick, and Massachusetts — and nowhere over the interior, should 

 it be sustained by future observations, would show that, as the Silurian 

 age opened, the continent, on the east at least, was raised nearly to its 

 present limits above the sea. The beds of St. John, New Brunswick, 

 bear evident marks, as Matthew observes, of sea-shore origin. The 

 eastern sea-coast of Acadian time was therefore not far from the pres- 

 ent line ; and the dry land of North America for a while may have 

 approximated in extent to that now existing. 



