MACTRA 



Plate IV. 



Species 13. (Mus. Cuming.) 



M.vcTRA GLAUCA. Mad. teatd ovato-tramwraa, teiittknla, 

 tumidiusculd, suhaquilaterali, sub ejiiderm'uJe Jlavidd 

 vel sqnalide fmcescente, palUde glaucd, radiis Iielvis 

 numerosis ornatd; Immld aredque mdistinctis, wnho- 

 nibus parvis, tumidimculis, approximatis, interdum 

 paUide violaceis ; denfibus lateralibus elonyatis, lamel- 

 Iceforndbns, in valcd dextrd duplmbm ; sinu palUi la- 

 tissimo, brevi, semicirculari. 



The glaucous Mactra. Shell ovately transverse, rather 

 tliin, somewhat swollen, nearly equilateral, smooth, 

 pale glaucous, ornamented with numerous light red 

 rays beneath a yellowish or dirty-brown epidermis ; 

 lunule and area indistinct, umboes small, rather 

 swollen, approximated, sometimes violet-tinged ; la- 

 teral teeth elongated, lamelliforra, double in the right 

 valve ; sinus of the mantle very broad, short, semi- 

 circular. 



BoRX, ]Miis. Cees. Vindobonensis, p. 51. pi. 3. f. 11, 13. 

 Mactra kelvacea, Chemnitz. 

 Mactra Neapotitana, Poll. 



Hab. European Seas. ~ 



The epidermis of this well-known European species is 

 of a close fibrous silky character. 



Species 14. (Mus. Cuming). 



Mactea jEauiLATERA. Mact. testd triatigidari, aqiiUa- 

 terali, tiimidd, Imv'ujatd, aiitice striata, albo-grised, 

 cuticuld Jiavesceute indutd, aiitice posticeqiie angulatd, 

 latere postico piano, lata, angido aciito circiimscripto ; 

 lunuld permagnd, depressd, cum aream, Icevigatd; val- 

 vis crassis, intus tiitldis, albo-griseis ; cardine atigusto, 

 crasso, brevi; dente carditiali parvo ; deutibus latera- 

 libus crassis, brevibus, antico longiore ; sinu pallii lata, 

 profuudu, semielUptico. 



The EQUILATERAL Mactra. Shell triangular, equi- 

 lateral, swollen, smooth, striated anteriorly, whitish- 

 grey, covered with a yellowish cuticle, angled an- 

 teriorly and posteriorly, posterior side flat, broad, 

 forming a sharp angle ; lunule very large, depressed, 

 and, with the area, smooth ; valves thick, shining 

 within, whitish-grey ; hinge-narrow, thick, short ; 

 cardinal tooth small ; lateral teeth thick, short, an- 

 terior the longer; sinus of the mantle broad, deep, 

 semielliptic. 



Deshayes, Pro. Zool. Soc. ISS-t. 



Hob. New Zealand ; Earl. 



A solid triangular shell, BonaxAWe on the posterior 



side, and bearing some resemblance in general aspect to 

 M. Speugleri. 



Species 15. (Mus. Cuming.) 



Mactra stultortjm. Ifact. testd ovato-subtrigond, eequi- 

 laterali, Icevigatd, interdum hie illic obsolete sulcata, 

 violaceo-cinered, rufescente tinctd et radiatd, umborii- 

 bus brevibus, approximatis ; ared gibbosiiisculd, angulo 

 obtiisissimo circumscriptd ; intus violaced. 



The fools' Mactea. Shell ovately subtriangular, equi- 

 lateral, smooth, sometimes here and there obsoletely 

 grooved, violet-ash, tinged and rayed with pale red, 

 iimboes short, approximated ; area rather gibbons, 

 surrounded by a very obtuse angle ; violet in the in- 

 terior. 



Cardimn stultorum, Linn<eus, Syst. Nat. (10th edit.) p. 681. 

 Mactra stultorum, Linnseus (Syst. Nat. 12th edit.). 

 Mactra rotundata, Gmelin. 

 Trigonella radiata, Da Costa. 

 Tellina radiata, Pennant. 

 Mactra lactea, Potiez and Michaud. 

 Mactra solida, Payraudeau. 



Hab. European Seas. 



This commonest of all species ranges throughout the 

 seas of Europe, from Norway to the Mediterranean. 



Species 16. (Mus. Cuming.) 



Mactra exoleta. Mact. testd ovato-transversd, oblique 

 cord aid, tenui, ventricosd, Icevi vel siibtilksime striata, 

 epidermide tenui fulvd corned indutd, latere antico 

 atlenuato, compressiusculo, cuneiformi, postico lata, 

 oblique angulato, ad angulum tenuicarinato ; hinuld 

 inconHpicud, hi medio cristatd ; ared perampld. 



The worn Mactra. Shell ovately transverse, obliquely 

 cordate, thin, ventricose, smooth or finely striated, 

 covered with a thin fulvous horny epidermis, anterior 

 side attenuated, rather compressed, wedge-shaped, 

 posterior broad, obliquely angled, slightly keeled at 

 the angle ; lunule inconspicuous, crested in the mid- 

 dle ; area very large. 



Gray, Mag. Nat. Hist. 1837, p. 372. 



Hab. Cape Horn and West Columbia. 



A very light ventricose species, peculiarly cordately im- 

 pressed on the anterior side, with the margins of the 

 valves rising through the centre of the lunule into an ele- 

 vated crest. The epidermis is of a thin horny deciduous 

 character. 



March, 1854. 



