630 E. ETHERIDGE 01ST THE PALAEONTOLOGY OF THE 



This variable and ubiquitous shell is tolerably abundant and 

 occurs at Feilden Isthmus ; the specimens agree in every particular 

 with the Scotch, Russian, Spitzbergen, and American examples. 

 It seems to be abundant in Illinois and Iowa with other widely 

 spread species ; finding this in iat. 82° 43' tends to show clearly the 

 connexion and continuity of the Worth-American Carboniferous fauna 

 northwards and towards Grinnell Land. Our specimens, six in 

 number, are from Feilden Isthmus, the most northerly land known. 



Log. Feilden Isthmus, lat. 82° 43'. 



Productus, sp., allied to punutatus, Martin, Anomites, Petrif. Derb. 

 t. 37. f. 6. 



Productus punctatus, Dav. Monogr. Brit. Carb. Brach., Pal. Soc. 

 p. 172, t. 44. f. 9-16. 



P. tubidisjoinosus, M'Chesney, Descr. New Sp. of Foss. from the 

 Pal. Rocks of the Western States, p. 37. 



So many forms have been referred to this species by British and 

 foreign authors that some excuse may be made for referring a soli- 

 tary specimen in a denuded state to so variable a shell. Productus 

 punctatus and Productus Jimbriatus much resemble each other, the 

 lines of growth varying in both, being either wide apart or closely 

 set; the hair-like spines on Productus punctatus are much more 

 numerous than on Productus Jimbriatus. 



This shell occurs everywhere in Britain, is abundant on the Con- 

 tinent, and has received the name of Productus tubulispinosus by 

 M'Chesney for specimens occurring in the Western States of Ame- 

 rica. Only two specimens have occurred in the Arctic collection. 

 I doubt not the species. 



Loc. Feilden Isthmus, lat. 82° 43'. 



PftODUCTUS MESOLOBUS, Phill. 



Producta mesoloba, Phill. Geol. Yorkshire, vol. ii. p. 215, t. 7. 

 f. 12, 13; De Kon. Anim. Foss. du Terr. Carb. Belg. t. 12. f. 8; 

 De Yern. Russia and Ural Mountains, vol. ii. t. 16. f. 8; Dav. Monogr. 

 Carb. Brachiopoda, Pal. Soc. p. 178, t. 31. f. 6-9. 



The projecting articulate expansions which constitute the attenu- 

 ated cardinal extremities, and rounded lateral margins, characteristi- 

 cally distinguish this shell from all other species. The ventral valve 

 is singularly gibbous at the umbo or beak. A few tubercles on the 

 surface of the shell show the position of small tubular spines. Like 

 most of the Producti in the collection, this is also a widely distri- 

 buted species ; it ranges from the Ural chain at Ilinsk to North 

 America and the Polar regions, where it was collected by Captain 

 Feilden at Feilden Isthmus, lat. 82° 43'. 



Productus eimbriatus, Sow. 



Productus Jimbriatus, Sow. Min. Con. vol. v. p. 85, t. 459. f. 1 ; 

 Dav. Monogr. Brit. Carb. Brach.. Pal. Soc. p. 171, t. 33. f. 12-15. 

 We possess only one specimen of this species ; it is a more finely 



