323 
Var. B. Testa atro-violacea, maculis nivosis irregulariter sparsis. 
intus violaceo-alba. 
Var. y. Testa roseo-purpurascente, fusco eleganter pauci-radiata, 
maculis albis nubeculata, intus albo-purpurascente. 
Hab. Moluccas. Coll. Cuming. 
26. Psammosia Layarot, Desh. P. testa elongato-transversa, de- 
pressa, equilaterali, transversim oblique et minute striata, striis 
ad latus posticum valve sinistre abrupte terminatis, in valva 
dextra continuis, et supra angulum obtusum lineis tenuibus longi- 
tudinalibus decussatis ; latere antico semi-elliptico, superne con- 
vexiusculo; latere postico angulo subcarinato distincto, superne 
recto, non declivi, paulo angustiore, extremitate obtuso; valvis 
solidiusculis, extus pallide roseo-violaceis, albo irregulariter macu- 
latis et fusco subradiatis, intus albo-purpurascentibus, nymphis 
obscure violaceo tinctis. 
Hab. Philippines. 
27. PSAMMOBIA ORNATA, Desh. P. testa ovato-transversa, sub- 
ventricosa, solida, inequilaterali, elliptica, albo pallide violas- 
cente, violaceo pallido marmorata, albo maculata, et rubro-cas- 
taneo interruptim radiata, ad umbones rufa, intus albo-violacea, 
in medio macula rufa notata; latere antico paulo longiore, late 
obtuso, postico equaliter lato, obtuso, transversim et oblique tenue 
striato, striis in valva sinistra ad latus posticum, levigatum in- 
terruptis, in valva dextra cum rugis posticalibus undulatis conti- 
nuis ; nymphis brevibus, violaceis; sinu pallii magno, profundo, 
late obtuso. 
Var. 3. Testa depressiore, pallidiore, striis rugisque crassioribus. 
Hab. Philippines, Ticao. Coll. Cuming. 
28. PsammMosiaA AMa=NA, Desh. P. testa elongato-transversa, 
angusta, depressa, tenui, pellucida, equilaterali, transversim regu- 
lariter striata, striis antice latioribus, in medio furcatis, postice 
in valva dextra evanescentibus, subobsoletis, in valva sinistra con- 
tinuis, striis octo radiantibus decussatis, alba, pallidissime violas- 
cente, violaceo pallido tenue maculata et obsolete radiata ; latere 
antico superne fere recto, paululum declivi, sensim attenuato, 
postico paulo latiore, oblique truncato, superne recto, vix declivi, 
angulo obtusissimo ab umbonibus decurrente distincto, margine 
inferiore fere recto ; ligamento prominente, cylindraceo ; valvis 
intus albis, nymphis violaceis. 
Hab. ? Coll. Cuming. 
29. PsammosiA PALLIDA, Desh. P. testa transversa, compressi- 
uscula, tenui, hyalina, subequilaterali, pallide sulphurea vel violas- 
cente, obscure violaceo pallido radiata, latere untico paulo bre- 
viore, attenuato, superne paulo declivi, postico latiore, subflexuoso, 
oblique truncato, levigato ; cardine angusto ; nymphis elongatis, 
angustis, violaceo-roseis ; sinu pallii subtrigono, horizontali, apice 
acuminato, superne declivi ; valvis oblique eleganter striatis, striis 
