﻿150 



dilated, compressed and very oblique; rather concave above, to receive the 

 ligament, which is partly internal, and partly external. 



S. australis, S. Mediterranea. 



Amphidesma. Shell transverse, inequilateral, subovate or rounded, some- 

 times gaping a little at the sides; hinge having one or two teeth, and a narrow 

 pit for the internal ligament. Ligament double; one external, short; the 

 other internal, fixed in the cardinal pits. 



A. variegata, 

 ' donacilla, 

 ' lactea, 

 ' cornea, 



A. albella, 

 ' lucinalis, 

 ' Boysii, 

 ' tenuis, 



A. variegatum, 



pulchrum, (Sowerby, C. 111. f. 2. 



pallidum, 



forme-sum, 



roseum, 



ellipticum, 



australe, 



corrugatum, 



subtruncatum, 



Z. P. 



3. 



8. 



1. 

 f. 17. 



4. 

 18. 

 10,20. 



solidum, (Gray, Sp. Z. Part I. pi. vi. f. 6. 

 cordiforme, (Chemnitz, xi. 1941, 1042. 

 rupium, (Sowerby, C. 111. f. 10. 

 cancellation, (Sowerby, Sp. C. f. 8. 



A. flexuosa, 

 ' prismatica, 

 ' phaseolina, 

 ' corbuloides, 



A. lamellosum, 



' reticulatum, 



' crenulatum, 



' duplicatum, 



' punctatum, 



' purpurascens, 



' multicostatum, 



' lenticulare, 



' lceve, 



' prismaticum, 



' tenue, 



' Boysii, 



' Siculum, 



A. glabrella, 

 ' purpurascens, 

 ' nucleola, 

 ' physoides. 



(Sowerby, Sp. C. f. 0, 10. 

 11, 12. 

 13. 



14, 15. 

 C. 111. f. 7. 

 5. 

 Sp. C. f. 16. 

 C. 111. " 



Sp. C. 



0. 



0. 



f. 21. 



22. 



23. 



24. 



CORBULEA.— Two Genera. 



Shell inequivalve, ligament interior. 



Corbula. Shell regular, inequivalve, inequilateral, closed or very slightly 

 gaping. One large conical, curved, ascending tooth in each valve, with a 

 pit beside it; no lateral teeth. Ligament internal, inserted in the pits. 



C. australis, 

 ' sulcata, 

 ' erythrodon, 



C. ovalina, 

 ' Taitensis, 

 ' nucleus, 



C. impressa, 

 ' porcina, 



C. semen, 



4 fossil species. 



Pandora. Shell regular, inequivalve, inequilateral, transversely oblong, 

 upper valve flat, and the lower convex. Two oblong, diverging, unequal, 

 cardinal teeth in the upper valve; two oblong pits in the other. Ligament 

 internal. 



P. rostrata, 



P. obtusa. 



