MESODESMA.— Plate III. 



" riorly rounded, anteriorly obtusely angled, anterior 

 area oblong-cordate; concentrically wrinkle-ridged, 

 smooth at the umboes. 



Deshayes, Anim. sans vert. vol. vi. p. 133. 

 Crassatella glabrata, Lamarck. 



Hab. Australia. 



The shell figured in Conch. Systematica under this 

 name is M. eryc'maa, a shell smooth and covered with a 

 polished horny epidermis throughout. Lamarck charac- 

 terizes his C glabrata as being grooved. 



Species 21. (Mus. Cuming.) 



Mesodesma NoVjE-Zelandi.e. Mes. testa oblongo-ovatd, 

 transversa, solidiu^euld, siibaquilaterali, lateribus ro- 

 tundatu, antico paululum breviore ; albidd, irregula- 



riter striata, epidermide tenui cornea fulvescente-albd 

 nitente indtitd. 



The New Zealand Mesodesma. Shell oblong-ovate, 

 transverse, rather solid, nearly equilateral, sides 

 rounded, anterior a little the shorter ; whitish, irre- 

 gularly striated, covered with a thin fulvous-white 

 shining horny epidermis. 



Mya Nova-Zelandite, Chemnitz, Conch. Cab. vol. vi. pi. 3. 

 f. 19, 20. 



Mya austraUs, Gmelin. 

 Mactra austraUs, Dillwyn. 

 Mesodesma Chenmitzii, Deshayes. 



Eab. New Zealand ; Earl. 



Chiefly distinguished by its transverse form, which has 

 no inclination whatever to the Donax form characteristic 

 of this genus. 



