133 



(living) in Richmond Gulf, Hudson Bay, in 15 to 25 fathoms, muddy 

 bottom, by A. P. Low, in 1899. 



The whole surface of each valve of St. Lawrence specimens of A. 

 crebricostata, as its name implies, is concentrically ribbed. Thus, in a speci- 

 men about 20 mm. in length, there are about twenty-one distinct and 

 prominent concentric ribs, and if the beaks had not been a little eroded, 

 there would have been a few more. But, in specimens of A. crenata irom the 

 same region, the ribbing is much finer and it would seem that it is only the 

 upper half of each valve (i. e the part inclusive of the beak, and half way 

 to the ventral margin) that is ribbed, the lower half being coarsely and 

 irregularly striai.ed concentrically. The largest St. Lawrence specimen of 

 A. crenata that the writer has seen is 25 mm. long, and on its outer surface 

 there ai'e about 25 concentric ribs in the upper lialf of each valve. The three 

 comparatively small specimens from Hudson Bay are irregularly striated 

 all over. 



ASTARTE CASTANEA, Say. 



Venus castanea, Say (1822). 



Astarte castanea, Say (1830) ; et auct. 



Bay of Fundy, 5 to 20 fathoms, not common (Verrill) ; Annapolis Basin, 

 N.S., rare (Verkruzen); Indian Springs, east side of Cape Blomidon, 

 Minas Basin, 1875 (G. T. Kennedy): Halifax Harbour (Willis); off Cape 

 Sable, N.S. (Verrill); Sable Island, 1899 (Prof. Macouu). 



A New England species, which does not seem to range farther to the 

 northward than the Bay of Fundy and Atlantic coast of Nova Scotia. 



Astarte quadrans, Gould. 



Astarte quadrans, Gould (1841 and 1870). 

 Astarte Portlandica, Mighels (1843) ; variety. 



Grand Manan, " occurs very rarely here " (Stimpson) ; Bay of Fundy, in 

 6 to 40 fathoms, not uncommon (Verrill) ; north shore of the St. Lawrence, 

 off Esquimaux Point (J. Richardson, Jun.) 



The " var. Portlandica occurs, with intermediate forms, in Casco Bay and 

 Bay of Fundy, 1 to 25 fathoms, not common ; " (Verrill). 



Astarte Banksii (Leach). Typical form. 



Venus compressa, Montagu (1808) ; non L.-Fide S. Wood, and G. O. Sars. 

 Venus Montacxdi, Dillw'yn (1817). 



Nicania Banksii, Leach (1819) ; and Sabine (1824) teste Moller. 

 Venus Montnijui, W. Wood (1825). 

 Astarte Banksii, MiiUer (1842). 

 Ifirania B>inksii, forma typica, G. O. Sars (1878). 



Off Halifax, N.S. (Stimpson, fide Packard) ; Le Have Bank, N.S., U. S. 

 Fish Commission, 1872, (Smith and Harger). Common in the northern and 



