MACTRA. 



Plate XVI. 



Species 79. (Mas. Cuming.) 



M.\CTRA GIBBOSULA. Mact. testa suhlrigono-cordatd, te- 

 nuiculd, (jibbom, inaqmlaturali, triinsvarsiiu jUiformi- 

 striatd, versus imbones Itsvigatd, alba, ferrugiiwo-fiis- 

 cesceiite palUdissime tinctd, latere antico breiv., pos- 

 tico declwi, obtuse angulatd; umbonibus tumidis, ntrin- 

 que angulatis, approximatis ; lunula aredque tatiusoit- 

 lis, eleganter pUcatis, medio elevatis. 



The gibbous Mactra. Shell somewhat triangularly 

 cordate, rather thiu, gibbous, inequilateral, trans- 

 versely thread-like striated, smooth towards the um- 

 boes, white, faintly tinged with rust-brown, anterior 

 side short, posterior slanting, obtusely angled ; um- 

 boes swollen, angled on each side, close ; lunule and 

 area rather broad, elegantly plicated, raised in the 

 middle. 



Deshayes, Pro. Zool. Soe. 1854. 



Hab. Indian Seas. 



A thin swollen species, having somewhat the general 

 aspect of a Cardinm. 



Species 80. (Mus. Cuming.) 



Mactea decora. Mact. testa ovato-transversd, turgidd, 

 iruBquilaterali, nitidd, alba et violaceo eleganter radiald 

 et traiiswrshn zouatd, latere antico breviore, obtuso, 

 transversim tenue regulariter sulcata, sulcis in medio 

 evanescentibus ; umbonibus tumidiusculis, atro-violaceis, 

 parum dktantibus ; lunula albo et violaceo bicoloratd, 

 regulariter plicatd, area concaviusculd, tenuiplicatd. 



The handsome Mactra. Shell ovately transverse, 

 swollen, inequilateral, shining, elegantly rayed and 

 transversely zoned with white and violet, anterior 

 side the shorter, obtuse, transversely finely irregularly 

 grooved, gTooves disappearing towards the middle; 

 umboes rather swollen, dark violet, but little distant ; 

 lunule two-coloured with white and violet, regularly 

 plicated, area rather concave, thinly plicated. 



Deshayes, Pro. Zool. Soc. 1854. 



HaJj. ? 



Of a Cijtherea aspect, grooved on the anterior half, ele- 

 gantly banded and faintly rayed with cinereous violet. 



Species 81. (Mus. Cuming.) 



Mactra Luzonica. Mact. testa transversim trigond, 

 aqnilatei'ali, subsymmelrice turgiduld, aqualiter utro- 

 que latere declivi, latere antico subobsolete sulcato, sul- 

 cis in medio plus minus evanescentibus, nitidd, palUde 

 fused vel albo-rufescente, in latere postico castaned, ex- 

 tremitatibus aqualifer obtusis ; timbonibus minimis, 

 acutis, apice violaceis ; lunuld aredque subcequalibus, 

 regulariter plicatis, violaceo maculatis. 



The Luzon Mactra. Shell transversely triangular, equi- 

 lateral, rather symmetrically swollen, slanting equally 

 on each side, anterior side faintly grooved, the grooves 

 more or less fading in the middle, shining, pale brown 

 or whitish-red, chestnut on the posterior side, extre- 

 mities equally obtuse; umboes very small, sharp, 

 violet at the apex; lunule and area nearly equal, re- 

 gularly plicated, spotted with violet. 



Deshayes, Pro. Zool. Soc. 1854. 



Hab. Island of Luzon, Phibppines. 



A smooth reddish-ash fawn shell, violet-tipped at the 

 umboes, chiefly remarkable for its equilateral oblong trian- 

 eular form. 



Species 83. (Mus. Cuming.) 



Mactra mera. Mact. testa ovato-lrigond, turgiduld, Icevi- 

 gatd, nitidd, inaquilaterali, corneo-favescente, ad uni- 

 bones rufescente, zomdis transversalibus saturatioribus 

 distanter interruptd, intus corneo-rufescente, latere an- 

 tico paulo breviore, obtuso, superne declivi et convexius- 

 culo, postico attenuato, valde declivi, mnbones versus 

 convexiusculo ; umbonibus depressis, parum obliquis, 

 approximatis, acutis; lunuld aredque ovatis, tumidius- 

 culis, regulariter plicatis. 



The plain Mactra. Shell ovately triangular, rather 

 swollen, smooth, shining, inequilateral, horny-yellow- 

 ish, reddish at the umboes, distantly interrupted with 

 darker transverse zones, interior horny-red, anterior 

 side a little the shorter, obtuse, slanting and rather 

 convex at the upper part, posterior side attenuated, 

 very slanting, rather convex towards the umboes ; 

 umboes depressed, a little oblique, approximated, 

 sharp ; lunule and area ovate, rather swollen, regu- 

 larly plicated. 



Deshayes, Pro. Zool. Soc. 1854. 



May, 1854. 



