Physical Structure and older stratified Deposits of Devonshire. 695 



trica, A. decussata, A. striatula ; also a smooth and a plaited species ; 

 Lepfcena caperata, L. scahricula ? Pecten s. n. Pallastra s.n.* All these shells 

 are found both among the calcareous slates of Pethervvin and in the calcareous 

 slates near Barnstaple ; and several of the species common to both localities 

 are extremely abundant. That there are several species among the Pethervvin 

 fossils w^hich have not been yet found among those of Barnstaple, takes not at 

 all from the force of our direct evidence. It deserves remark, that there are 

 several species in these upper groups which do not appear in the lower; and 

 among those we may notice the Goniatitesandthe Endosiphonitesf, (Clymenia 

 of Munster,) as they seem to point towards the types of the carboniferous 

 period. 



In the lower division of the Barnstaple calcareous slates occur the Marwood 

 fossils, given in our lists, among which are several species of Cucullaa. 

 These shells are associated with the genus Bellerophon, one of which, as be- 

 fore stated, cannot be distinguished from the Bellerophon glohatus of the old 

 red sandstone. Very nearly on the strike of the Marwood beds occur the 

 fossil plants of the Sloly quarries. According to Professor Lindley, {ante, 

 p. 683.) one of the species belongs either to a Stigmaria or a Lepidodendron ; 

 while others are new or incapable of determination. Professor Henslow, who 

 has recently examined a good series of fossil plants from the same locality, in- 

 forms us, that he is able out of them to distinguish three or four species, not 

 one of which he believes to have been described in the published works of 

 Sternberg, Brogniart, or Lindley. Either of these results would fall in with 

 our present views. We undoubtedly consider the Sloly beds as out of the 

 limits of the carboniferous series, and therefore we should expect that its fossils 

 would conform to an older type. On the other hand, the appearance of a few 

 species of the true carboniferous fossils in the upper division of the old red 

 sandstone would be in perfect harmony with what we know of the geological 

 distribution of organic forms. But the assumption that the ordinary species 

 of coal-measure plants may exist in the old graj/wacke rocks of an entirely 

 distinct period, takes for granted conditions which are not supported by the 

 evidence of the Devonian sections, as we now interpret them. 



We are unwilling to push our present remarks any further; but we can 



* Some of the fossils quoted are of doubtful species ; but the doubt does not apply to the iden- 

 tification of the individual specimens from the opposite sides of the culm-trough. 



t The appropriate name of Endosiphonite had been given to the genus by Mr. Ansted before he 

 was acquainted with the previous discovery of Count Munster. The name Clymenia is by no 

 means so good ; but having the priority, ought to be retained. We cannot but regret that tiie 

 original name [Planulites) was rejected by Count Munster, as it harmonizes with the general no- 

 menclature of fossil Cej)hatopodes, better than his present name Clymenia. 



