MESODESiMA.— Plate I. 



Species 3. (Mus. Cuming.) 



Mesodesma angusta. Mes. testa trigono-elongatd, an- 

 gustd, compressiiisculd, valde inaquilaterali, latere an- 

 tico brevissimo, fruncato ; leevigatd, nitente, epidermide 

 olivaceo-luted indutd. 



The narrow Mesodesma. Shell triangularly elongated, 

 narrow, rather compressed, very inequilateral, ante- 

 rior side very short, truncated ; smooth, shining, co- 

 vered with an olivaceous-yellovv epidermis. 



Deshayes, MS. (Mus. Cuming.) 



Hab. ? 



A very inequilateral Zlowaa'-shaped species, of a smooth 

 shining aspect, much compressed towards the posterior 

 end. 



Species 4. (Mus. Cuming.) 



Mesodesma lata. Mes. testd trigono-ovatd, laid, com- 

 pressd, concentrice dense irregularlter strlatd, striis ad 

 latera sulcaiioribus, latere postico rotuudato, autico 

 Hiulto breviore, augulato-truncatd, wnboiiibus subpla- 

 nulatis ; albidd, epidermide corned, palUde lutescente, 

 indutd. 



The begad Mesodesma. Shell triangularly ovate, broad, 

 compressed, concentrically densely irregularly stri- 

 ated, stria; more grooved at the sides, posterior side 

 rounded, anterior much shorter, augularly truncated, 

 umboes rather flattened ; whitish, covered with a 

 pale yellow-horny epidermis. 



Deshayes, MS. (Mus. Cumiug.) 



Hab. New Zealand. 



A fine broad subcompressed species, angularly truncated 

 down the anterior side, rounded at the posterior. 



Species 5. (Mus. Cuming.) • 



Mesodesma elongata. Mes. testd elongato-oblongd, so- 

 lidiuscnld, valdi inceqidlaterali, latere postico com- 

 presso-producto et rotmidato, antico brevissimo, trun- 

 cato ; albidd, epidermide lutesceute-corned nitente in- 

 dutd. 



The elongated Mesodema. Shell elongately oblong, 

 rather solid, very inequilateral, posterior side com- 



pressly produced and rounded, anterior very short, 

 truncated ; whitish, covered with a shining yeUowish- 

 horny epidermis. 



Deshayes, MS. (Mus. Cuming.) 



Hab. Eaiues' Island, Torres Straits ; Ince. 



Of an unusually elongated form, very shortly truncated 

 at the anterior end, compressly produced at the posterior. 



Species 6. (Mus. Cuming.) 



Mesodesma nitida. Mes. testd siibtrigono-elongatd, valde 

 ineequilaterali, latere antico brevissimo, crasso, tutnidi- 

 nsculo, trimcaio, postico compresso-producto et rotun- 

 dato; nitente-albd, epidermide luiescente-corned versus 

 marginem indutd. 



The shining Mesodesma. Shell somewhat triangu- 

 larly elongated, very inequilateral, anterior side very 

 short, thick, rather swollen, truncated, posterior com- 

 pressly produced and rounded ; shining- white, co- 

 vered towards the margin with a yellowish-horny 

 epidermis. 



Deshayes, MS. (Mus. Cuming.) 



Hab. ? 



Closely allied to the preceding, from which it differs in 

 being thicker and more swollen at tiie jwstcrior end. 



Species 7. (Mus. Cuming.) 



Mesodesma ovalis. Mes. testd oblongo-ovali, tenuiculd, 

 versus marginem comp?-essd, suhaquilaierali, latere pos- 

 tico vix angustiore ; nitente-albd, subobscure striata, 

 epidermide nigricante partim indutd. 



The oval Mesodesma. Shell oblong-oval, rather thin, 

 compressed towards the margin, nearly equilateral, 

 posterior side a little the narrower ; shining white, 

 rather obscurely striated, partially covered with a 

 blackish epidermis. 



Deshayes, MS. (Mus. Cuming.) 



Hab. New Zealand ; Hart. 



Of a distinct typical form from the preceding species, 

 rather thin and nearly equilateral, partially covered with a 

 thin black epidermis. 



