ATRACHIA. ANODONTIN.E. 381 



SuB-FAM. 4. ANODONTINiE. 



Cardinal teeth none ; lateral tooth extending along the 

 hinge or entirely wanting; hinge margin generally 

 winged, 



Lamproscapha Sw. Shell not winged, elongate pod- 

 shaped ; teeth none; bosses near the anterior ex- 

 tremity. Tropical America only? 

 L.? elongata Sw. Zool, 111. i. 176. siliquosa, Braz. Test, 

 ensiforme Spix. Braz. Test. pygmea. lb. ^ 



Symphynota* Lea. A single or double lamellar tooth 

 extending the whole length of the hinge margin ; 

 valves generally winged and connate. (Jig. 123. i.) 

 plicata Z-eac/i. Zool. Miss. f ? tenuissima. Am. Tr. iii. 



lavissima Lea. Am.Tr. iii. pi. 11. f. 21.| 



pi. 13. f. 23. rubens. En. Meth. 201. f. 1. 



bialata Zm. lb. pi. 14.f. 24. 



Anodon Lam. Doubly winged; no lamellar or other 

 teeth. 



A. cataracta Lam. vi. 1. cygnea Lam. Gualt. pi. 7. 



p. 85. f. F. 



Hemiodon Sw. Shell ovate ; tubercles or undulations 

 on the hinge margin^, representing cardinal teeth. 

 H. undulatus. {An. rugosus purpurascens Zool. 111. i. 160. 

 Zool. 111. i. 96.) areolata. Id. ii. 18. 



Patularia Sw. Shell nearly equilateral, round or cor- 

 date ; no teeth. 

 T. ovata Sw. Ex. Conch, pi. 36. rotundatus, lb. pi. 137. 



SuB-FAM. 5. ALASMODONTIN^. 



Lateral teeth entirely wanting ; cardinal teeth one or 

 two. 



* Dipaus Leach. 



f Differs from bialata by having oblique depressions towards the bosses 

 or beaks, which latter also are woMnarked with "concentric undulations." 



J Seems to form the passage to Anodon. Specimens labelled by Mr. Lea, 

 were totally different from my Hem. purpurascciis. 



