MACTRA, 



Plate VIII. 



Species 29. (Mus. Cuming.) 



Mactra alata. Mact. testa ovato-trigond, obliqud, con- 

 vexd, incc(jtdlaterali, tramversim irregidariter minute 

 striata, candidissimd, jiellucidd, epidermide tenui stra- 

 minea versus marginem indutd ; latere antico suhatte- 

 nuato, postico latiore, angulato, ad angulum carina fo- 

 liaced lamellari alato ; umhonihus acute angulatis ; lu- 

 nula indistiuctd, medio valde elevatd, area perampld, 

 plano-excavatd. 



The winged Mactea. SheU ovately triangular, oblique, 

 convex, inequilateral, transversely irregularly mi- 

 nutely striated, very white, transparent, covered to- 

 wards the margin with a light straw-coloured epider- 

 mis, anterior side subattenuated, posterior broader, 

 angled, winged at the angle with a lamellar foliaceous 

 keel ; mnboes sharply angled ; lunule indistinct, much 

 raised in the middle, area very large, ilatly excavated. 



Spenglek, Sbiv. Naturch. Selsk. vol. v. part 2. p. 99. 

 Mactra cariiiata, Lamarck. 



Hab. West Columbia ; Cuming. 



WcU distinguished by the conspicuous curly foliaceous 

 keel, that rises on the angle in each valve bordering the 

 posterior area. 



Species 30. (Mus. Cuming.) 



Mactra ovata. Mact. testa ovatd, turgidd, Jdante, sub- 

 (B([tdlaterali, rude tratisversim striata, squalide fulvd, 

 ocliraceo tinctd, latere antico obtuso, postico subatte- 

 nuato ; unibonibus tumidis, oppositis, confertis ; lunula 

 aredque indistinctis, intus medio pallida awantid. 



The ovate Mactra. Shell ovate, swollen, gaping, nearly 

 equilateral, rudely transversely striated, dirty-fulvous, 

 ochre-stained, anterior side obtuse, posterior subat- 

 tenuated; umboes swollen, opposite, close; lunule 

 and area indistinct, interior pale orange iu the middle. 



Spisula ovata. Gray, Fauna of New Zealand, p. 251. 



Hab. New Zealand. 



A duU swollen shell, in-egulai-ly rudely striated, tinged 

 with orange in the iuterior. 



Species 31. (Mus. CumLug.) 



Mactra exijiia. Mact. testa otato-transversd, aqnila- 

 terali, extrendtatibus ambabus cequaliter obtusis, trans- 



versim minufissime striata, purpurascente-cinered, iu- 

 carnato-radiatd, epidermide fibrosa pdvd versus mar- 

 ginem indutd; lunuld aredque amplis, subindistinciis, 

 in medio elevatis, ehganter plicato-liratis ; umbonibus 

 tumidiuscuUs, approximalis ; sinupallii brevissimo, lato, 

 regulariter arcuato. 



The pretty Mactra. Shell ovately transverse, equi- 

 lateral, both extremities equally obtuse, transversely 

 very minutely striated, purple-ash, flesh-rayed, co- 

 vered towards the margins with a fibrous fulvous 

 epidermis; lunule and area large, rather indistinct, 

 raised in the middle, elegantly plicately ridged ; um- 

 boes rather swollen, approximated ; sinus of the 

 mantle very short, broad, regularly arched. 



Deshayes, Pro. Zool. Soc. 1854. 



Hab. Moreton Bay, Australia ; Strange. 



A very characteristic species, minutely striated in the 

 middle, whilst on the area and lunule it is strongly ele- 

 gantly plicately ridged. 



Species 32. (Mus. Cuming.) 



Mactra edulis. Mact. testa ovato-trigond, crassd, so- 

 lidd, cequilaterali, tdrinque subangtdatd, sordide albd, 

 femgineo-rufo interdum hie illic tinctd, plus ndniis 

 erosd, epidermide oUvaced partim indutd; lunuld 

 aredque indistinctis, medio suhelevatis ; umbonibus tu- 

 midiuscuUs, oppositis; sinu pallii trigono, obtuso, 

 brevi, liorizontali. 



The eatable ]\Iactea. Shell ovately triangular, thick, 

 solid, equilateral, slightly angled on both sides, dirty- 

 white, sometimes tinged here and there with rust-red, 

 more or less eroded, partially covered with an olive 

 epidermis ; lunule and area indistinct, slightly raised 

 in the middle ; umboes rather swollen, opposite ; 

 sinus of the mantle triangular, obtuse, short, hori- 

 zontal. 



King, Zoological Journal, vol. v. p. 335. 

 Muliida edulis. Gray. 

 Mulinia bicolor. Gray. 

 Mulinia ti/pica. Gray. 



Hab. Patagonia and Straits of J\Iagellan. 



A dingy suberoded solid shell, extremely variable in 

 form according to its variety of growth. 



April, 1854. 



