230 Miscellaneous. 



Family Anatenid^e. 



Cyathodonta, Con. 

 An inequivalved bivalve ; hinge with a broad, not very projecting, 

 cartilage-fosset, which is carinated near the margin ; muscular im- 

 pressions rounded, indistinct ; pallial impression with a large rounded 

 sinus. 



C. undulata. Subovate, inequilateral, very thin and fragile, with 

 obliquely concentric undulations, profound on the anterior side, and 

 suddenly becoming obsolete towards the posterior extremity, which 

 is truncated and direct ; posterior slope of the deeper valve obscurely 

 tricarinated ; cartilage-pit robust ; valves with minute, very closely 

 arranged, granulated radiating lines. 1 2-10 : 1 nearly. 



Family Pholadid^. 

 Pholadopsis, Con. 

 Inequivalved ; right valve produced posteriorly, left valve over- 

 lapping the opposite ; cartilage situated on a projecting callus. 



P. pectinata. Ovate, very thin and fragile, profoundly gaping 

 posteriorly ; profoundly ventricose anteriorly ; valves with elevated 

 waved laminae terminating near a profound sinus, which extends 

 from beak to base ; right valve undulated near the posterior end, 

 reflected, margin pectinated ; both valves have concentric lines. 



Parapholas, Con. 

 P. bisulcata. Ovate-oblong ; anterior accessory valves or deposit 

 strong, shining, gibbous on the margin of aperture, and having 

 obscure decussated striae, the transverse ones a little raised ; anterior 

 side of the larger valves with numerous prominent crenulated radii ; 

 a slightly oblique sulcus extends from beak to base, and a slightly 

 impressed line runs from the beak to the posterior end of the closed 

 portion of the base ; between the two impressed transverse lines the 

 valves have closely-arranged, rugose, longitudinal laminae, and pos- 

 terior to these the laminae are remote and elevated. 2^. 



Penitella. 



P. Wilsonii. Ovate-oblong, very thin, profoundly ventricose ; 

 valves with a furrow from beak to base ; the papyraceous anterior 

 valves very wide; anterior valves with numerous oblique waved 

 laminae and radiating acute ribs ; ligament margin sinuous ; posterior 

 side with concentric distant undulations ; two small accessory valves 

 behind the beak, which are reflected posteriorly ; membranaceous 

 appendage M'itli a sinuous or concave margin where it joins the 

 shell, and a deep annular groove anterior to the middle. 2^. 



Triton. 

 T. perforatus. Subpyriform ; volutions 5 or 6 ; ribs revolving, 

 flattened, slightly prominent, wide and narrow alternately, with 

 narrow interstices, and an occasional revolving line ; angle of body 

 whorl tuberculated ; spire scalariform, the angle of each whorl with a 

 tuberculated rib or carina; colour cinereous; epidermis brown, rough, 

 hairy, longitudinally ribbed ; aperture wide ; margin of labrum sinu- 



