MACTRA. 



Plate III. 



Species 9. (Miis. Cuming.) 



Mactra eutescens. Mact. testa ovato-trigond, inceqiii- 

 laterali, crassd, soJ'uld, lateribus plaiid et subangidald, 

 fransversim sulcato-pUcatis, plicis irregidarUer flex- 

 uoso-corrugatis ; alba, I'lifescente plus riiiuus tinctd, ad 

 umbones indistinct^ rudiatd, latere antico attenuato, 

 subrostrato, jmstico angiilnto ; ared luauMque mag- 

 iiis, Jiexurd circumdaiis, iiitus alba, sinu pallii brevi ; 

 dent.ibiis cardiiinlibus vnlidis. 



The keddish Mactra. Shell ovately triangular, in- 

 equilateral, thick, solid, flat and rather angled at the 

 sides, transversely groove-plaited, plaits irregularly 

 flexuously wrinkled ; white, more or less stained with 

 red, indistinctly rayed at the umboes, anterior side 

 attenuated and a little beaked, posterior angled ; area 

 and lunule large, surrounded with a flexure, interior 

 white, sinus of the mantle short ; cardinal teeth 

 strong. 



Lamarck, Anira. sans vert. (Deshayes'edit.) vol. vi. p. 103. 



Hab. Van Diemen's Land. 



A solid flexuously wrinkled shell, having very much the 

 form of a gibbous Crassatetla, but without the rich brown 

 epidermis characteristic of that genus. 



Species 10. (Mus. Cuming.) 



Mactka sericea. Mact. testd ovato-traiisvend, tenui, 

 coinpressd, medio tumidiusculd, subaquilaterali, latere 

 antico rotiindato, postico subattemcato, paulutum Jii- 

 ante, laeigatd, versus marginem tenuistriatd, albd, 

 epidermide fasceseente sericea indiitd ; ared lunnldque 

 vix couvexis, subtiliter plicato-striatis, umbouibus par- 

 vis, ad apices violaceis ; cardine angusto, dentibiis la- 

 teralibus elongatis, fossuld profunda, sinu pallii ob- 

 lique ascendente. 



The silky Mactra. Shell ovately transverse, thin, 

 compressed, rather swollen in the middle, nearly equi- 

 lateral, anterior side rounded, posterior rather attenu- 

 ated and a little gaping, smooth, finely striated to- 

 wards the margin, white, covered with a light brown 

 silky epidermis ; area and lunule scarcely convex, 

 finely plicately striated, umboes small, violet-tinged 

 at the tips ; hinge narrow, lateral teeth elongated, pit 

 deep, sinus of the mantle obliquely ascending. 



Deshayes, Pro. Zool. Soc. 1854. 



Hab. ? 



A thin compressed transverse species, rather swollen 

 towards the umboes, covered with a light brown silky epi- 

 dermis. Umboes violet at the tips. 



Species 11. (Mus. Cuming.) 



Mactra epidermia. Mact. testd ovato-transversd, tenui, 

 coinpressd, albidd, epidermide fuscescente sericea in- 

 dutd, subaquilaterali, latere antico rotundato, postico 

 sublongiore, pauluUmJlexuoso-carinuluto; lunula ared- 

 que angustis, elongatis. 



The clothed Mactra. Shell ovately transverse, thin, 

 compressed, whitish, covered with a light brown silky 

 epidermis, nearly equilateral, anterior side rounded, 

 posterior rather longer and slightly flexuously keeled ; 

 lunule and area narrow, elongated. 



Deshayes, Pro. Zool. Soc. 1854. 



Hab. Faro, Portugal. 



A thin compressed species, slightly flexuously keeled 

 down the posterior side, covered with a light brown silky 

 epidermis. 



Species 12. (Mus. Cuming.) 



Mactra striatella. Mact. testa ovato-cordatd, veutrl- 

 cosd, tenuiculd, Candida, epidermide tenuissimi indutd, 

 incequilaterali, latere antico rotundato, postico sitban- 

 gulato-producio, Idante, suhtiiiter irregularUer concen- 

 trice striata, uinbonibus approximaiis, corrugato-pli- 

 catis ; cardine breviusculo, fared subcirculari. 



The finely striated Mactra. Shell ovately heart- 

 shaped, ventricose, rather thin, white, covered with 

 a very slight epidermis, inequilateral, anterior sifle 

 rounded, posterior subangularly produced and gap- 

 ing, finely irregularly concentrically striated, umboes 

 approximated, corrugately plaited ; hinge rather short, 

 pit subcircular. 



Lamarck, Anim. sans vert. (Deshayes' edit.) vol. vi. p. 98. 

 Enc. Meth. pi. 255. f. 1. 

 Spisida striatella, Gray. 

 Mactra albina, Deshayes. 



Hub. ? 



A fine large white species, covered with a very thin cu- 

 ticular epidermis, characteristically wrinkle-plaited about 

 the umboes. 



March, 1854. 



