MACTRA. 



Plate XIV. 



Species 65. (Mus. Cuming.) 



Mactra aspessa. Mad. testa elongato-transversd, ellip- 

 ticd, compressd, inaq^uilaterali, latere postico aidico 

 duplo longiore, trausversim irregulariter tenuisidcatd 

 et striatd, alhd, maculh epidernddis niyro-fuscce pecu- 

 liar der notatd ; umbouibMS parvis, approximatis. 



The spkinkled Mactra. Shell elongately transverse, 

 elliptic, compressed, inequilateral, posterior side twice 

 as long as the anterior, transversely irregularly finely 

 grooved and striated, white, peculiarly marked with 

 spots of black-brown epidermis ; umboes small, ap- 

 proximated. 



SowERBY, Tankerville Catalogue, Appendix, p. 2. 

 Spisula tenera, Gray. 



Hab. Philippine Islands ; Cuming. 



The characteristic dark spots of this species reside only 

 in the epidermis. 



Species 66. (Mus. Cuming.) 



Mactra ovalina. Mad. testd ovato-transversd, subaqid- 

 laterali, compressd, albd, hyaUnd, tennissime iransver- 

 sim striatd, tdriiiqite obtusd ; itniboiubus jtarvis, Icevi- 

 natis, approximatis ; ared lanceolatd, depresslone bica- 

 rinatd subfiexuosd utrinque notatd, lunuld angustd, de- 

 jiressiuscidd ; sinu pallii snbdHptico, in medio latiore. 



The ovaline Mactra. SheU ovately transverse, nearly 

 equilateral, compressed, white, hyaline, very finely 

 transversely striated, obtuse at both ends ; umboes 

 small, smooth, approximated ; area lanceolate, with 

 a bicarinate subfiexuous depression on each side, lu- 

 nule narrow, rather depressed ; sinus of the mantle 

 subelliptic, broader in the middle. 



Lamarck, Auim. sans vert. (Deshayes' edit.) vol. vi. p. 104. 



Hab. West Columbia ; Cuming. 



A compressed subtransparent white shell, with a cha- 

 racteristic two-keeled fiexuous depression down each side 

 of the area. 



Species 67. (Mus. Cuming.) 



Mactra depressa. Mad. testd ovato-transversd, siibtri- 

 ffond, incequilaterali, depressd, tranwershn irregulariter 

 tenuistriatd, albd, sub epidermide tenui stramined, latere 

 antico superne concaviusculo, postico convexiusculo ; 



liinnld aredque sublanceolatis ; cardine lato, soUdius- 

 culo, dentibus lateralibus brevibus ; sinu pallii lato, 

 oblique arcuato. 



The DEPRESSED Mactra. Shell ovately transverse, sub- 

 triangular, inequilateral, depressed, transversely irre- 

 gularly finely striated, white, beneath a light straw- 

 coloured epidermis, anterior side rather concave at 

 the upper part, posterior rather convex ; lunule and 

 area sublanceolate ; hinge broad, rather solid ; lateral 

 teeth short ; sinus of the mantle broad and obliquely 

 arched. 



Spengler, Skriv. Naturch. Selsk. vol. v. p. 118. 



Eab. Australia. 



Of very simple oval form, obtusely rounded at each end. 



Species 68. (Mus. Cuming.) 



Mactra Sadli^. Mad. testd ovatd, subtrigond, aqui- 

 laterali, depressd, plana, extremitatibus rotundatd et 

 hiante, sub epidermide sericed albd fusco-violaceo-ra- 

 diatd ; lunuld aredque angustis, macula fusco-violaced 

 noiatis; valvis tenuibus, fragilibus, transversim temd- 

 striatis ; sinu pallii lato. 



Saul's Mactra. Shell ovate, subtriangidar, equilateral, 

 depressed, flat, rounded and gaping at the extremi- 

 ties, white, rayed with brown-violet, beneath a silky 

 epidermis ; lunule and area naiTow, marked with 

 fuscous- violet ; valves thin and fragile, transversely 

 finely striated ; sinus of the mantle broad. 



Gray, Ann. and Mag. Nat. Hist. 1837. 



Hab. Senegal. 



A very distinct and well-marked species, remarkable 

 for its fine transversely fibrous silky epidermis. 



Species 69. (Mus. Cuming.) 



Mactra tristis. Mad. testd suborbiculari, valde com- 

 pressd, incequilaterali, utrinque hiante, squalide albd, 

 suberosd, versus marginem epidermide fusco indutd, 

 transversim irregulariter dense striatd, latere antico 

 brevi, rotundaio, postico duplo longiore, leviter jlexuoso- 

 angidato ; imibonibus minimis, approximatis ,• lumdd 

 aredque indistindis ; sinu pallii magno, obtuso, basi 

 dilatato. 



The sad Mactra. Shell suborbicular, very compressed. 



April, 1854. 



