157 
very open: some are altogether rose-coloured, others rosy on one 
side, yellow on the other, and blackish in the middle; others again 
almost entirely of a bluish tint, and mingled with these various co- 
lours. 
The summit, sometimes almost entire or decorticated only, is at 
other times entirely eroded at its inferior surface; it is prolonged 
upon the posterior margin of the opening, though not beyond, and 
there it is worn away, as if it had been rubbed upon a grindstone. 
5. Navicetza Cumineiana. N. testd orbiculari seu ovatd, convexd, 
solidd, vix striatd luteo-fuscescente, lineis concentricis nigris un- 
dulatis arcuatisve interdum reticulatis cinctd; apice marginali 
eroso, retuso ; labio plano, albo, antice in medio producto ; aperturd 
albd, cordiformi. 
Var. 3. T. nigro-reticulatd, lutescente maculatd et subfasciatd. . 
Var. y. T. ovato-ellipticd, dilute olivaced, postic? lineolis nigris 
transversis, interdum majoribus et remotis notatd. 
Hab. Var. a et c from a mountain-stream in the island of Cama- 
guing. Var. 6 from Cagayan, island of Mindanao. 
Long. 1:00 ad 1°20; lat. 0°84 ad 0°92; conv. 0°40 ad 0°56 poll. 
The columella is 0°24 to 0:28 poll. in diameter. 
Operculum irregularly oval, of an uniform white or rayed with 
rose-colour above, profoundly notched anteriorly ; the notch rounded 
at its base. The apophysary rib is only apparent at the anterior 
summit of the operculum ; it projects but little, and is nearly acute. 
Its external margin is oblong, very thin and very smooth ; the left or 
opposite margin is striated, somewhat imbricated above, and crenu- 
lated throughout its extent. The inferior surface is of a pale uniform 
flesh-colour. The subrotund or oboval muscular impression is of a 
rose-red anteriorly, and of a dark red at the base. Upon the oper- 
culum of the var. y the left margin is completely wanting, which 
gives an oblong and a subtriangular form to the muscular impres- 
sion. These characters are only accidental. 
I have dedicated this interesting species to Mr. Cuming, whose 
numerous discoveries in natural history have enriched science with 
a crowd of new facts, as a testimony of my esteem. 
6. NaviceLta Ciyrzoium. N. testd ovato-oblongd, antic? et postice 
rotundatd, tenue et concentriceé striatd, lineolis nigro-violaceis seu 
purpurascentibus, interdum confluentibus et maculis albido-lutescen- 
tibus oblongis elongatisve nigro-marginatis sub-serialibus et passem 
radiis paliidis binis pictd ; apice brevi ad dextram via obliquante, 
“ante marginem posito ; labio semilunari, conveziusculo, fuscescente ; 
aperturd patuld. 
Var. 3. T. olivaceo-nigricante, maculis obsoletis ; apice eroso ; labio 
latiore, carneo, in medio subproducto, recto. 
Var. y. T. olivaced, lutescente maculata, in medio ventre obsolete 
biradiatd ; apice purpurascente, labio fuscescente. 
Var. 6. T. atratd, immaculatd ; apice eroso ; labio et margine aper- 
ture carneo-fuscescentibus. 
Var. e. T. nigrescente lineolatd pallide virescente radiatd et macu- 
latd, apice submarginali roseo, integerrimo, 
