M Y T I HI S 



Species 15. (Mus. Cuming.) 

 Mytiia's hostratus. Myt. testa mbelongatd, versus 

 umbones attenuatd el rostrata, longitudinaliter tenui- 

 striatd, striis imdalis, hie illic ohsoletis, latere postico 

 obtuse inciirw, antico rotnudato ; purpiireo-nigrd. 

 The beakeb Mytilus. Shell rather elongated, atte- 

 nuated towards the umboes and beaked, longitudi- 

 nally finely striated, striae waved, here and there 

 obsolete, posterior side obtusely incurved, anterior 

 rounded ; purple-blaek. . 



DuNKER, W- in Mus. Cuming. 'i ^ 

 Hab. Tasmania. 



Of rather elongated form, attenuated towards the um- 

 boes, which are produced into a sharp beak. The strire 

 are very superfieial. The colouring is very dark, only 

 sliowing purple where bruised. 



Species IG. (Mus. Cuming.) 



MvTiLUS siNUATts. Myt. testa obloiii/o-flabelliformi, 

 peculiariter arcuatd, obtuse gibbosd, Ifevlgatd, anfice 

 cottcentrice striata, latere postico mtdio incurvo, antico 

 d^iclivi-rotundato ; nigricante-viridi, nigra obscure len- 

 tigittosd. 



The sinuated Mytilus. Shell oblong fan-shaped, pe- 

 culiarly arched, obtusely gibbous, smooth, anteriorly 

 concenirically striated, posterior side much incurved, 

 anterior slopingly rounded ; very dark green, ob- 

 scurely freckled with black. 



Dlwkeb, MS. in Mus. Cuming. 



Hab. Philippine Islands ; Cuming. 



Distinguished by its peculiarly arched gibbous growth, 

 and dark sreen freckled colouring. 



Species 17. (Mus. Cuming.) 



Mytilus Dunkeri. Myt. testa trigmo-Jlabelliformi, 

 postice plano-incurvd et gibhosd, antice declivi-com- 

 pressd, versus umbones .iubanguste rostrata, radiatim 

 superfcialiter striata, striis concentricis decussatd ; 

 niteute-atrd. 



Dunker's Mytilus. Shell triangularly fan-shaped, pos- 

 teriorly flatly incurved and gibbous, anteriorly slo- 

 pingly compressed, towards the umboes rather nar- 

 rowly beaked, radiately superficially striated, decus- 

 sated with concentric strife ; shining black. 



Hab. Philippine Islands. 



I have the pleasure of naming this fiue species after the 

 intelligent naturalist of Cassel, who has worked with so 

 much zeal on the specimens of Mytilacece in Mr. Cuming's 

 cabinet. It is a shining black shell, of a conspicuous fau- 

 siiape, broadly gibbous and incurved on the posterior side, 

 with the umboes coutracted and beaked. 



Species IS. (Mus. Cuming.) 

 Mytilus cuneifor.his. Myt. testa elongato-oblongd, 

 regulariter rotundato-trigoud, latere postico brevissimo, 

 versus um/jones peculiariter declivi-conlorto, latere an- 

 tico pralongo, compresso ; leeoigatd, vel obsolete decu/s- 

 satim striatd ; nitente-corned, intense viridi, postice 

 luteo-castaned. 

 The WEDGE-snAPED Mytilus. Shell elongately ob- 

 long, regularly rotuudately triangular, posterior sidt- 

 very short, peculiarly slopingly twisted towards the 

 umboes, anterior side very long, compressed ; smooth 

 or obsoletely decussately striated ; shining horuy, 

 very dark green, posteriorly yellowish-chestnut. 

 Hah. Bay of Guayaquil (on mud-banks); Cuming. 



Of a dark shining horny-green, passing ou the posterior 

 side into chestnut, with the interior delicately purple- 

 stained. The curious posteriorly contorted attenuation of 

 this shell near the umboes renders it easily recognized. 



Species 19. (Mus. Cuming.) 

 Mytilus pallio-punctatus. Myt. testd elougato-flabet- 

 formi, solidd, gibbosd, versus umbones attemiato-ros- 

 tratd, latere postico late incurvo ; intense purpureo- 

 nigrd. 

 The mantle-dotted Mytilus. Shell elongately fan- 

 shaped, solid, gibbous, attcnuately beaked towards 

 the umboes, posterior side broadly incurved ; dee[) 

 purple-black. . 



DuNKER,>IS. in Mus. Cuming. ' ^ ^ 

 Hab. California and Mazutlan. 



This species is always so much eroded it is not possible 

 to describe the sculpture. It appears however to be deve- 

 loped originally in fine radiating striae. Mr. Carpenter 

 describes it, in his Catalogue of the Reigen Collection in 

 the British Museum, as being abundant at Mazatlan, and 

 always similarly eroded. 



August, 1857. 



