80 



Four of the Inocerami from Maud and Lina Islands, and all from the 

 other localities, are either so imperfect or so much crushed out of shape 

 that it is impossible to determine satisfactorily to what species they 

 belong; still, as stated above, it is most probable that they are all 

 I. concentricus. 



I. conceutricus is abundant in the Cretaceous rocks of man}'- localities 

 in Europe. It is most characteristic of the Gault, but is found also in 

 the Upper Greensand. It has not yet been recorded as occurring on the 

 mainland of North America. 



The species was first described b}^ Parkinson in Vol, V. of the First 

 Series of the " Transactions of the Geological Societ}' of London, 1820," 

 but a reference to the original description is purjDOsely omitted above, 

 because the writer has not had the opportunity of consulting it. 



Melina mytiloides (?) (Lamarck. Sp.) 



Penia mytiloides, (?) Lamarck. " Animaux sans Vertebres." Second Edition. Vol. 

 VII., page 19. 



Perna mytiloides, (?) Damon. " Su^jplement to the Geology of Weymouth and 

 the Island of Portland," Plate II., fig. 5. 



Perna mytiloides, (?) Phillips. " Geology of Oxford and the Valley of the Thames,'' 



Plate XV., fig. 5. 



Fig. 8. ■ 



Fig. 8. — A, B, C, D. — Outlines of four specimens of Melina mytiloides (?), about one- 

 third of the natural size. The original of fig. A, though little more than half grown, 

 is the only one in which the hinge and beaks are perfect ; in fig. C, the lower half of 

 the shell is entire ; the other two are partly restored from the lines of growth. 



Shell nearly equivalved, compreBsed, thickest near the anterior margin ; 

 general outline elliptic-ovate, obliquelj' truncate above; height much 



