38 



Generally resembling M. expleta in form and coloration, but differ- 

 ing in size and the want of striae in the middle area. It is marked 

 like M. strigata Hanley, a larger and less dilated shell. 



MoDiOLARiA cuxEATA. T. oblique ovato-cuneata, ventricosa, 

 tenuis ; epidermide pallide virente ; umbonibus terminalibus exstanti- 

 bus decurvis ; margine dorsali cristata, arcuatu ; facie dorsali lata, 

 declivi ; angulo antico-ventrali late rotundato ; margine ventrali 

 aliquid pendente ; extrem. posticfi anguste rotundata ; areis termi- 

 nalibus radiatim sulcatis, sulcis quadratis punctatis, anticis 16, posticis 

 30 ; area intermedia concentrice striata : pagina interior vinaceo 

 tincta vel marmorata ; margine crenulata. Long. 12; alt. et lat. 7 

 millim. Inhabits False Bay, Cape Good Hope, at low-water mark, 

 imbedded in the test of a large Ascidian, sometimes a dozen in an 

 individual ; also among rocks, 20 fathoms. W. S. 



Very similar to M. inarmoj'afa, differing chiefly in being of a brown- 

 ish or rosy color instead of pale green ; the umbonal slope is more 

 angular, and the point more acute ; the strife are rather more numer- 

 ous and more deeply impressed. 



M. ARCUATA. T. parvula, gracilis, arcuata ; margine ventrali in- 

 curvata ; fastlglo antero-dorsali elevato ; umbonibus ad quadrantem an- 

 teriorem ventrieosis ; areis terminalibus concinne radlato-striatis ; area 

 mediana inornata. Long. 5 ; alt. 2 millim. Inhabits Kagoslma. W. S. 



M. QUADRULA. T. subquadrata, marginibus parallelis, ventrali 

 vix incurvata ; extremitate antica rotundata ; extrem. postica, oblique 

 truncata ; apicibus fere terminalibus ; declivitate postero-dorsali 

 modice exposito ; areis terminalibus radlato-striatis ; area mediana 

 inornata. Long, 10; alt. 5 millim. Inhabits Kagoslma. W. S. 



The two latter descriptions are taken from two single valves, quite 

 unusual in form ; perhaps accidentally distorted. 



Mytilus coruscus. T. pjTiformis, margine ligamentali vix 

 arcuata ; marg. postero-ventrali angulata, late truncata ; regione 

 byssali lente Incurvata ; facie antica, lata angulo submarginali limitata ; 

 epidermide crassa picea antlce castanea ; margine interior! nigra : 

 cavositas ad cicatrices ex viridi Irlcolor argillaceo versus apicem 

 mutata. Long. 65 ; alt. 38 ; lat. 2.5 millim. Inhabits Hakodadi 

 Bay, common on rocks between tide marks. W. S. 



A very symmetrical species, quite remarkable for the brilliancy of 

 its interior. 



Mytilus mutabilis. T. elongata, margine byssali fere recta ; 

 marg. dorsali lente omnino arcuata in marginem ventralem continua ; 

 umbonibus pallldis, acutis, plerumque erosis ; valvis versus aplccm 

 radiatim sulcatis, sulcis sensim evanescentibus, alibi glabris, epidermide 

 castanea nitlda indutis; facie ventrali concinne striata : cavositas 

 hepatlca. Long. 30; alt. 16; lat. 12 millim. Inhabits Kagoslma 

 Bay. W. S. 



