220 CKUISE OF THE NEPTUNE 



of Coccjsteus sp., Holoptychius sp., and Modolia angusta. In 

 the same strata with these were also seen indeterminable plant- 

 fossils. Slightly higher up in the profile, however, in a black 

 shale which occurred in two lentiform masses, eighteen inches 

 and six feet in thickness, were found numerous plant-fossils.' 



' Professor Nathorst, of Stockholm, who has kindly under- 

 taken the examination of these, says that among others are 

 Archceopteris fissilis Schmalh. and Arch, archetypus Schmalh., 

 both characteristic of Upper Devonian. In examining the 

 material collected, Professor Uathorst also found with the plant 

 remains some remains of fishes.' 



From the above it will be seen that on the southern side of 

 Ellesmere there is a complete succession of strata, bearing fos- 

 sils from Middle Silurian age up to the Upper Devonian. These 

 strata have an aggregate thickness of 8,000 feet, and form- the 

 thickest and most carefully measured section of the Silurian 

 and Devonian beds of the Arctics. 



On the southern and southwestern parts of North Devon the 

 Silurian strata are much thinner than those described by Schei. 

 At Cuming creek the Archa3an gneisses were found overlain 

 unconformably by red and purple arenaceous shales and thin 

 bedded Sandstones having an aggregate thickness of fifty to one 

 hundred feet. These in turn were succeeded by beds of impure 

 limestone of light-gray or creamy colour. The beds are usually 

 under two feet in thickness, and separated by thinner beds con- 

 taining a considerable amount of clay. These light-coloured 

 limestones have a thickness of over 1,000 feet in the cliffs on 

 both sides of the creek. The sides of the cliffs are covered with 

 broken limestone, so that it was impossible to measure a section 

 up them, but in two or three places a darker coloured limestone 

 conglomerate was found, made up of small pebbles cemented by 

 a dark shaly matrix. Fossils are only found in the beds imme- 

 diately overlying the dark shales and sandstones of the base. 



