1869.] 139 [Perkins. 



and hawks, have white unspotted eggs, or eggs sparsely 

 spotted, sometimes exhibiting these variations in the same 

 nest. Generally the earlier in the season the greater the 

 number and the brightness of these markings. 

 . A fish hawk that has been several times robbed, instead of 

 laying the usual highly colored egg peculiar to the species, 

 deposits one nearly white, and with very few light spots. 

 But here, in two instances at least, early in the season, the 

 eggs of the crow were unspotted, exhibiting only a light 

 greenish ground — an occurrence hitherto unrecorded, and not 

 easy of explanation. 



November 3, 1869. 

 The President in the chair. Thirty-three persons present. 



The following paper was presented : — 



The Molluscan Fauna of New Ha vex. Part II. Acephala 

 and Bryozoa. By George H. Perkins, Ph.D. 



LAMELLIBRANCHIATA. 



pholadim:. 



Cyrtopleura Tryon, 1867. 



Cyrtopleura truneata Tryon, Am. Journ. Conch., Vol. in, 

 No. 3, p. 2, App. Pholas truneata Say, Am. Conch., p. 107, 1822; 

 De Kay, Moll. N. Y., p. 248, pi. xxxiv, fig. 223 ; Sowerby, Thes. 

 Conch., Vol. ii, pi. civ, figs. 29, 30. 



Not rare in peat bogs and clay near high water mark, associated 

 with Mya and Petricola. Animal much larger than the shell, with 

 the mantle closed; gills two pairs, very long, meeting at the base of 

 the siphonal tube and extending some distance into it. Foot oval, 

 obliquely truncated at the end, across which runs a ridge from which 

 the surface is bevelled to the edges; palpi rather long, triangular; 



