CARDIAD^. 67 



small ; margins smootli ; ligament internal ; teeth 

 h h 1, or r, t» i- Animal with one siphon. 



K. suborbicularis. Fig. 102 ; n.s. 

 rubra. 



Turt07iia (Hanley). Shell oblong, unequal- 

 sided ; ligament concealed between the valves ; 

 hinge-teeth %. Animal with one siphon, lengthened. 

 T. miniita. Fig. 103 ; mag, 



Bijplodonta (Bronn.). Shell roundish, smooth ; 

 ligament double, rather long, sub-marginal ; hinge- 

 teeth f , the front tooth in the left valve, and the 

 hind one in the right, cleft ; muscular impressions 

 polished. Animal with the mantle-edges plain, 

 united ; siphons two, unfringed. 



D. rotundata. Fig. 104 ; n. s. 



104 105 



Lucina (Bruguiere) . Shell round, white ; beaks 

 depressed; lunule distinct ; ligament oblique^ semi- 

 internal ; teeth +' h h the laterals sometimes want- 

 ing ; muscular impressions rough. Animal with 

 the mantle open ; siphons two, simple ; foot cylin- 

 drical, pointed, slightly heeled. 



L. borealis. L. flexuosa. 



divaricata. leucoma. 



ferruginosa. sx^inifera. Fig. 105 ; ^ n. s. 



Family III. Cardiad^. 



Shell regular, heart-shaped, marked with alter- 

 nate ribs and furrows, radiating from the beaks ; 



f2 



