40 Mighels^ and Adams^ Descriptions of 



compressed ; is ,06 inch long, ,05 inch high, and ,025 inch 

 wide. It resembles C. minor ^ Nob., but the beaks in these 

 shells are approximate and proportionally larger ; this species 

 differs also in having the cardinal teeth obsolete both in the 

 young and mature shell, and it is much larger. 



NUCULA DELPHINODONTA. 



Plate IV. Fig. 5. 



N. testa parva, eolida, trigona, transverse sub-sulcata ; angulis umbonalibua 

 duobus'; natibus prorninentibus, sub-terminalibus ; dentibus anticis tribus, pos- 

 ticis septem, elevatis, conicis, acutis. 



Shell small, solid, very wide, oblique, triangular, trans- 

 versely ribbed and striate irregularly ; anterior margin nearly 

 straight above, curved below, inferior margin well rounded, 

 posterior moderately curved, making a right angle with the 

 anterior ; surface divided into three regions by the umbonial 

 angles which diverge from the beaks ; these are prominent, 

 nearly terminal, often eroded ; epidermis green ; seven poste- 

 rior and three anterior teeth, which are very long, slender and 

 pointed. 



Average length, ,13 inch; height, ,11 inch; width, ,09 

 inch. 



Cabinets of Bost. Soc. Nat. Hist., J. W. Mighels, and C. B. 

 Adams. 



Habitat. Casco Bay. Several hundred specimens were 

 taken from the stomach of a single haddock, in the spring of 

 1841. At several times subsequently we have obtained them 

 from the same source, sparingly. 



Remarks. This species is allied to N. proxima, Say, and 

 N. teiitiis, Turton, but is distinct from both in the number 

 and arrangement of the teeth ; also in respect to form, ante- 

 rior and posterior umbonial angles, and in its greater width. 



NUCULA CASCOENSIS. 

 Plate IV. Fig. G. 



N. testii ovato-lanceolatA, sub-inequilaterali, compressa ; postic^ attenuata; 

 areolfi valde compressa; natibus parvis ; dentibus anticis decern, posticis duo- 

 decim, parvis. 



Shell ovate-lanceolate, rather thin, finely striate, slightly 



