51 



Thkacia, (Sp. iindl.) 



Perhaps Corimya (? Thracia) Nicoleti, Agassiz. "Etudes critiques sur les Myes 

 Fossiles." Li\Taison IV., page 272. Plate XXXVII, figures 1-6. 

 Compare also Corimya Studeri Ag. ( = Tellina incerta, Thunu. ) 



Three broken and distorted casts of a typical species of Corimj^a (or 

 Tbrucia) whose shape and surface markings are undistinguishable from 

 those of the Corimya Nicoleti figured in the memoir above cited. In the 

 most perfect of these specimens there are two narrow grooves on the 

 right valve, which run obliquely from the hiuge margin, behind the beaks, 

 towards the upper part of the posterior end, but which are nearly parallel 

 to the superior border behind. These of course indicate the presence of 

 as many raised lines on the inner surface of that valve. Similar markings 

 on the interior of the valves are not shewn quite so distinctly in the 

 original illustrations ofC. Nicoleti, nor is anything said about them in the 

 text. Still, Mr. Eichardson's specimens agree in every essential point 

 with the description of that species, but they are so imperfect that their 

 identification is uncertain and must be so until a better series is obtained. 

 Goldfuss' figures of Corimya Studeri, under the name Tellina incerta, 

 Thurman, are also very like the Queen Charlotte Island shell. 



Most palaeontologists have agreed in uniting Agassiz's genus Corimya. 

 with TA/'aciV/ of Blainville, although this view was opposed by the late 

 Dr. Stoliczka. If the two genera are to be kept separate, the present 

 species, with its compressed rather than inflated form, and especiall}' in its 

 having "two long ribs running from the beaks posteriorly," belongs rather 

 to Corimya as re-defined by Stoliczka, than to Thracia proper. 



Pleuromya (?) Carlottensis. (N. Sp.) 



Plate IX, Figure 8. 



Shell slightly inequivalved, moderately convex in front, concavely 

 attenuate at the sides behind. Outline elliptic ovate, short and jaarrowlj" 

 rounded in front, produced and bluntly pointed at the base, posteriorly ; 

 length rather more than a third greater than the height. 



The beaks are situated at a distance of about one-fourth from the 

 anterior end; they are wide, l)ut not ver}- acute ; their apices are curved 

 inwards and a little forwards. Behind the unibones the hinge line is 

 nearly straight but somewhat concave, its general direction is downwards. 

 The ligamental area is lanceolate in outline, but not very clearly defined, 



