226 
21. Lucrna (Myrt#a) strancet, A. Adams. L. testa equila- 
terali, solida, ventricosula, lenticulari, albida, costellis radiantibus 
nodoso-squamosis, sculpta, concentrice sulcata, umbonibus media- 
nis, viv prominulis; intus incrassata, alba, margine ventralt 
crenulato, intus radiatim sulcato. 
Hab. Moreton Bay (Mr. Strange). Mus. Cuming. 
In most of its characters this species approaches L. (Myrtea) 
Layardii, but it is much more ventricose, and the radiating ribs are 
more imbricately squamose than in that species. 
22. DipLoponTa GLoBULosA, A. Adams. D. testa tenui, rotun- 
data, subglobosa, vix obliqua, sordide alba, concentrice striolata, 
umbonibus submedianis, anteversis, latere antico superne excavato, 
postico rotundato ; cardinis dentibus apicalibus duobus, divaricatis, 
subobsoletis, lateralibus nullis. 
Hab. Moreton Bay (Mr. Strange). Mus. Cuming. 
This species appears distinct from any hitherto described, although 
a great similarity runs through all the species of the genus. 
23. Youp1a GLortosa, A. Adams. Y. testa elongato-transversa, 
inequilaterali, utrinque hiante, lactea, tenui, subpellucida, nitente, 
latere antico breviore, rotundato, linea impressa, obliqua ex um- 
bonibus usque ad marginem ventralem, instructo ; latere postico 
acuminato-rostrato ; concentrice plicato-lirata, plicis tenuibus, 
confertis, postice obsoletis, antice distantioribus ; margine ventrali 
sinuato. 
Hab. Singapore. Mus. Cuming. 
A very large and splendid species, having somewhat the character 
of Y. lanceolata, Sow., but with the cartilage-pit nearer the anterior 
end, and with the fore part broad and rounded. 
24. Mactra pusitua, A.Adams. WM. testa subtrigono-ovata, equi- 
laterali, tenui, nitente, concentrice striata, latere postico subangu- 
lato, area elliptica longitudinaliter sulcata, latere antico longiore, 
subangulato ; rosaceo-albida, maculis roseis radiatim dispositis, 
irregulariter picta ; intus roseo variegata ; umbonibus rubiginosis. 
Hab. Moreton Bay (Mr. Strange). 
A small and prettily variegated species of Mactra, with the inte- 
rior showing the rosy markings of the valves, and of a shining ap- 
pearance externally. 
25. Ne#ra Fracitis, A. Adams. J. testa oblongo-ovata, com- 
pressiuscula, tenui, alba, vitrea, pellucida, nitida, concentrice 
striata, latere antico breviore, rotundato clauso, postico longiore, 
acuminato, subrostrato, hiante; margine ventrali postice sub- 
sinualo. 
Hab. Moreton Bay (Mr. Strange). Mus. Cuming. 
This is a delicate glassy and fragile species, somewhat resembling 
in external appearance a Yoldia. The cartilage is in a projecting 
cavity of the hinge-plate, and there are no lateral teeth. 
