628 R. ETHERIDOE ON THE PALAEONTOLOGY OE THE 



Spirifera and Productus contain (as might be expected) the greatest 

 number of individuals, yet the species are few — in Spirifera four, 

 Spiriferina one, Productus five, Streptorhynclius one, and Ilhyncho- 

 nella one. All the species are British except Spirifera Grimesi, an 

 American form, the others named having a wide distribution. 

 Peilden Isthmus must be a prolific locality, if thoroughly searched ; 

 for it is evident that a rich Carboniferous -limestone fauna reaches 

 this high latitude, 82° 43', and would indicate that the true Coal- 

 measures may be under the waters and ice of the Polar sea. Pour 

 genera with ten species of Polyzoa from the same locality accompany 

 the Brachiopoda ; but only one or two Corals came home in the col- 

 lection — a Syringopora and a Lithostrotion, evidently from the same 

 beds. 



Genus Spirifera, Sow. 1815. 



Spirifera duplicicosta, Phill. 



Spirifera duplicicosta, Phill. Geol. York. vol. ii. p. 218, 1. 10. f. 1; 

 Dav. Monogr. Carb. Brach., Pal. Soc. p. 24, t. 3. f. 7-10, t. 4. 

 f. 3, 5-11. 



This variable species corresponds with the description and figures 

 given by Mr. Davidson in his valuable Monograph upon the Carbo- 

 niferous Brachiopoda (loc. cit.). It does not appear to be common 

 in the Arctic rocks, only three specimens occurring in the collection. 

 One specimen resembles also Spirifera striata (Martin), which is a 

 closely allied species. Keyserling has described a species (Spvrifer 

 fasciger) from Petschora Land (Wissenschaftl. Beobacht. Petschora- 

 Land, t. 8. f. 3), which certainly is the same as our British form and 

 the Spirifera duplicicosta brought from Peilden Isthmus. 



This species is common and abundant, in space and time, through 

 the Carboniferous series ; occurs everywhere in Britain, and in many 

 places in Ireland, Belgium, &c. 



Loc. Peilden Isthmus, lat. 82° 43', in rough grey limestone. 



Spirifera, sp., allied to S. Grimesi, Hall, Geol. Iowa, vol. i. pt. 2, 

 p. 604, 1. 14. f. 1-5. (PI. XXY. fig. 5.) 



We only possess a portion of the ventral valve of this species, 

 which admirably shows the muscular impression; in the ventral 

 valve none of the outer shell occurs ; therefore whether it can be 

 referred to Hall's species is perhaps really doubtful. It appears to 

 have had a strongly incurved umbo. Hall's specimen came from 

 the Burlington Limestones of Iowa, lat. 40°. Captain Feilden's 

 single ventral valve is from Peilden Isthmus, lat. 82° 43', a latitu- 

 dinal difference of more than 40°. 



No description can be given of this portion of the shell, nor 

 can I refer it to any other known species : comparison with Hall's 

 figure (Joe. cit.) will show the close affinity. I figure it, however, 

 for the sake of reference and for the peculiarity of its great 

 muscular system. 



Loc. Peilden Isthmus, lat. 82° 43'. 



