UPPER DEVONIAN FISH REMAINS. 47 



Horizon. More or less complete scales appear to be somewhat 

 common in the fish horizon of Skrap Valley. One fragment from the 

 dark schists of Galgeodden, (S. I. 103) also presumably belongs to this. 

 category. 



Teeth with Dendrodont Structure. 

 (PI. VIII, figs 7-9). 



From the Fish horizon in Skrap Valley we have a series of teeth 

 with dendrodont structure, which may be assumed to belong to the forms 

 of which the scales are described above. The dimensions of the specimens 

 vary to some extent. I have depicted some of the best preserved, and 

 will now give a brief description of them. 



Description 1. Fig. 8, PI. VIII, shows a large, powerful tooth, 

 (S. I. 13) the point being broken. The length is 19 mm., the greatest 

 breadth about 8 mm. The cross section is round, although there are 

 distinct wedge-shaped edges. 



Another example resembles the foregoing, but increases more 

 markedly in breadth below. 



2. Quite small teeth, one of which (S. I. 42 b) is shown in fig. 7. 

 The type resembles that first described, but on the average is more 

 flattened. 



3. Long, slender teeth of a distinctly bent form (S. I. 42 a). The 

 cross section is almost round at the base, but towards the apex becomes 

 more and more oval. It is very sharply pointed. (Fig. 9). The length 

 varies from 911 mm. long, the greatest breadth 23 mm. 



Observations. Microscopic preparations have convinced me 

 regarding the dendrodont structure, which moreover is also indicated by 

 the close, fine, longitudinal ribs of the upper surface. 



The largest tooth mentioned in 1 reminds one of the type which 

 A. SMITH WOODWARD 1 classified with Dendrodus biporcatus OWEN, and 

 which he considers to belong to Holotychius giganteus AG. I therefore 

 believe that they must be accepted as teeth of Holoptychius Scheii, 

 nov. sp. The quite small ones which are mentioned in 2, might be 

 regarded as marginal teeth of the same form. Those mentioned in 3, 

 agree on the whole with the type classified by SMITH WOODWARD 2 as 



1 Catalogue, Vol. II. p. 338. 



2 Do. p. 339. 



