PART II. ATRACHIA. ANODONTINiE. 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 ; hosses near the anterior ex- 

 tremity. Tropical America only? 



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

 ensiforme Spix. Braz. Test. pygmea. IF). 



SympJiynota^ Lea. A single or double lamellar tooth 

 extending the whole length of the hinge margin ; 

 valves generally winged and connate, {fig. 123. ?.) 



plicata Leac/i. Zool. Miss f ? tenuissima. Am. Tr. iii. 



lavissima Lea. Am.Tr. iii. pi. 11. f. 21.j: 



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

 bialataZert. 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. 



Patulavia Sw. Shell nearly equilateral, round or cor- 

 date ; no teeth. 

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



SuB-rA3i. 5. ALASMODONTIN^. 



Lateral teeth entirely wanting ; cardinal teeth one or 

 two. 



* Dipsus Leach. 



f Differs from bialata by having oblique depressions towards the bosses 

 or beaks, which latter also are not marked with "concentric undulations." 



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

 were totally different from my Hem. purpurascens. ^ 



