596 R. ETHERIDGE ON THE PALAEONTOLOGY OE THE 



This is the Leptcena lata of Yon Buch and of the ' Silurian 

 System ' (loc. cit.), one of the most abundant shells of the Ludlow 

 group, especially in the upper division. In Scandinavia, Russia, 

 and North America this is also a very abundantly distributed shell. 



Loc, Cape Louis Napoleon, lat, 79° 38'. 



Genus Atrypa, Dalman, 1827. 



Atrypa phoca (Salt.). 



Rliynconella phoca, Salt. Sutherland's Journal, vol. ii. p. ccxxvi, 

 t. 5. f. 1-3. 



Several specimens of this species occur in the collection. Mr. Salter 

 referred Dr. Sutherland's specimens to the genus Rhynchonella. 

 More accurate knowledge of the Brachiopoda has clearly defined 

 those characters that essentially typify the genera. Mr. Salter par- 

 ticularly noticed the resemblance of this shell to Jurassic forms ; and 

 it certainly does approach the globose group of the Terebratulidse in 

 the Oolitic series. The absence of the umbonal foramen and delti- 

 dium, however, removes it at once from the Terebratidce or Rhyn- 

 chonellce, our shell being imperforate. Dr. Sutherland obtained his 

 specimens from Cape Riley, Cornwallis, Leopold, Griffith's, and Seal 

 Islands ; Mr. Hart collected his from Bessels Bay (lat. 81° 6'), and 

 Dr. Coppinger obtained it from Bessels Bay and Dobbin Bay (lat. 

 79° 41'), in much higher latitudes. There can be no doubt about 

 this species being the same as those collected by Dr. Sutherland 

 at the above places. 



Atrypa Mansonii (Salt.). 



Rliynconella Mansonii, Salt. loc. cit. p. ccxxi, t. 5. f. 5. 



We have two or three specimens of this species of Atrypa ; it is a 

 much smaller and flatter species than A. phoca, and has the mesial 

 fold more pronounced and sharper. The description by Salter in the 

 appendix to Sutherland's ' Journal ' contains all that need be said 

 relative to this species. 



Loc. Bessels Bay, 81° 6'. 



Atrypa reticularis (Linn.). 



Anomia reticularis, Linn. Syst. Nat. ed. 12, vol. i. p. 1152. 

 Atrypa reticularis, Dav. Mon. Brit. Sil. Brach., Pal. Soc. p. 129, 

 t. 14. f. 1-22. 



This shell is found everywhere throughout the Upper Silurian 

 series of the Arctic circle ; it is as common there as in the Wenlock 

 series of Britain, Scandinavia, and North America. The forms vary 

 (as with us) according to locality, life, and condition. The variety 

 aspera appears to be amongst them ; but of this I cannot be sure, 

 the species altogether being so variable. No Palaeozoic shell has a 

 wider space or geographical range, or greater range in time. With 

 us it characterizes the Silurian rocks from the Lower Llandovery to 

 the Upper Ludlow, and passes up into the Devonian ; and this holds 



