INSTITUTE of SCIENCE, PHILADELPHIA. 117 



fine concentric lines of growth, disposed in a somewhat interrupted 

 series ; teeth ? 



Length, .8 inch ; height, .7 inch. 



Several specimens which can be readily identified by their small size 

 and erect outline. 



1 Chama maorophylla, Chemnitz. 

 Conch. Cab., vii, p. 149. 

 Gabb, "Santo Domingo," Trans. Am. Philos. Soc., xv, p. 251. 



Numerous small shells, the largest not measuring over one inch in 

 greatest extent, which have a general resemblance to the recent form. In 

 the absence of larger specimens I prefer to consider the identification as 

 somewhat doubtful, seeing how very closely the young of different species 

 of Chama resemble one another. The species appears to be both dex- 

 tral and sinistral, unless, indeed, two distinct forms are represented by 

 the valves in my possession. One or more of the individuals are undis- 

 tinguishable from Conrad's Chama congrcgata (Miocene of the Atlantic 

 border). 



Lucina Hillsboroensis, nov. sp. Fig. 62. 



Shell (known only by the left valve) disciform, suborbicular, evenly 

 rounded anteriorly and basally, truncated posteriorly ; beak pointed, 

 sub-central; the pre-umbonal border rapidly declivous, direct; two ob- 

 lique, fairly prominent, cardinal teeth ; surface covered with numerous 

 regularly-placed, concentric and slightly flexuous, lamellae, about 

 eighteen to the inch, between which are seen finer lines. 



Length, 2.2 inches ; height, the same. 



Differs from Lucina disdfonnis, Heilpr., in its suborbicular outline ; 

 from the recent L. Ji/osa, apart from other characters, in lacking the 

 convexity of that species. 



Crassatella deformis, nov. sp. Fig. 63. 



Shell thick in substance, obliquely-oval, the beaks well anterior ; 

 anterior border, beginning at the beaks, evenly rounded; posterior border 

 abruptly truncated ; basal margin evenly rounded, not flexuous, crenu- 

 lated ; external surface profoundly sulcated, the slci not extending beyond 

 the angulation of the broad posterior slope, which is slightly hollowed, 

 and only shows the lines of growth. 



Length, nearly three inches ; height to summit of umbo, 1.7 inch. 



This species can be readily recognized by its oblique form, the broad 

 posterior slope, and the prominence of the sulcation. 



Cardita (Carditamera) serricosta, nov. sp. Fig. 64. 



Shell ventricose, obliquely-oval, highest in the anterior region ; um- 

 bones well anterior, very prominent, overlooking a deeply impressed, 



