1889.] NATURAL SCIENCES OF PHILADELPHIA. 141 



ON SOME NEW SPECIES OF MOLLUSCA FROM THE 

 BERMUDA ISLANDS. 



BY PROFESSOR ANGELO HEILPRIN. 



The following species were obtained in the summer of 1888, 

 during a brief sojourn with a class of students from the Academy 

 of Natural Sciences. 



Chama Bermudensis. PI. VIII, fig. 1. 



Shell thick, ponderous, sub-cordiform ; the right valve consider- 

 ably smaller than the left, but yet thicker and deeper than in most 

 Chamas ; beak of left valve prominent, spirally incurved ; ligamen- 

 tal furrow in left valve deep, arciform ; dental sulcus broad, moder- 

 ately deep, and supported interiorly by a prominent plate tooth. 



Muscular impressions elongated, not deep. External surface 

 roughly corrugated by the lines of growth. 



Height of shell (left valve), measured to top of beak about three 

 inches; length, measured along the antero-posterior axis 2 - 3 inches ; 

 thickness of single valve 1*2— 1*5 inch. 



Dredged in large quantities in Harrington Sound. 



Macoma eborea. PI. VIII, fig. 2. 



Shell moderately inequilateral, truncated in the lower half of the 

 posterior slope ; anterior slope regularly declivous, the posterior 

 flattened. Right valve with widely diverging cardinal teeth, the 

 space between which receives the double-tooth (grooved medially) of 

 the left valve ; lateral teeth in right valve. 



Pallial sinus large, extending more than half across the shell ; 

 external surface (white) concentrically and delicately lined by the 

 lines of growth. 



Length of shell three-quarters of an inch ; height, two-thirds of 

 an inch. 



Mysia pellucida. PI. VIII, fig. 3. 



Shell thin, convex, ovally orbicular ; the umbones moderately 

 prominent; nolunule; hinge-line linear, a single medially-grooved 

 cardinal tooth in the left valve (resembling Felanid). 



Adductor impressions oval, not much elongated. Shell white, 

 nearly smooth. Length of single specimen somewhat over a halt- 

 inch ; height the same. 



