214 G. LINDSTROM, ON THK SILURIAN CiASTROPODA AND I'TKKOPODA OF GOTLAND. 



I 



Plate IV. 



Fig- 1 — 7. Tremanotus longitudmalis n. p. 86, all specimens from Wisby, f. 5 dorsal keel with apertures, 

 from a cast, f. 6 magnified details of the same, showing septa like, curved lines, going 

 transversally, marking where apertiiral lamelliB have been situated. 

 » 8 — 12. Tremanotus compresstis n. p. 87, from Ostergarn. 

 » 13 — 15. Bellerophon trilobatus Sow., p. 80, from Petesvik, Habblingbo. 



