Zoological Society. 145 



' ^roso, retuso; labio piano, albo, antice in medio producto ; aperturd 



albd, cordiformi. 

 Var. ft. T. nigro-reticulatd, lutescente maculatd et subfasciatd. 

 Var. y. T. ovato-ellipticd, dilute olivaced, postice lineolis nigris 



transversis , interdum majoribus et remotis notatd. 

 Hab. Var. a et c from a mountain-stream in the island of Cama- 

 guing. Var. ft 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. Navicella Clypeolum. N. testd ovato-oblongd, antic^ et postice 

 rotundatd, tenue et concentrice striatd, lineolis nigro-violaceis sen 

 purpurascentibus, interdum conjluentibus et maculis albido-lutescen- 

 tibus oblongis elongatisve nigro-marginatis subserialibus et passim 

 radiis pallidis binis pictd ; apice brevi ad dextram vix obliquante, 

 ante marginem posito ; labio semilunari, convexiusculo,fuscescente ; 

 aperturd patuld. 

 Var. ft. T. olivaceo-nigricante, maculis obsoletis ; apice eroso ; labio 



latiore, cameo, in medio subproducto, recto. 

 Var. y. T. olivaced, lutescente maculatd, in medio ventre obsolete 



biradiatd ', apice purpurascente, labio fuscescente. 

 Var. Z. T. atratd, immaculatd ; apice eroso ; labio et margine aper- 

 tures carneo-fuscescentibus . 

 Var. e. T. nigrescente lineolatd pallide virescente radiatd et macu- 

 latd, apice submarginali roseo, integerrimo. 

 Var. ^. T. fuscescente maculis linearibus albidis nigro acut^ margi- 

 natis obsoletis sparsis variegatd ; apice purpurascente ; labio et 

 margine aperturae dilute fuscis. 

 Long. 0*80 ad 1-32 ; lat. 0*76 ad 0*92 ; conv. 0*24 ad 0-48 poll. 

 Hab. Var. ft and y from Cagayan. Var. a and e from Banguey, 

 province of North Ylocos, island of Lu9on : found on stones in a 

 mountain stream. Var. y, island of Guimaras, on the rocky bed of 

 a small stream. Var. h, rocky bed of a stream in the mountains of 

 the isle of Negros. The type itself is found at Pasuguing, province 

 of North Ylocos, island of Lu^on. 



Operculum almost square, thin, of a rose-colour, cut squarely an- 

 Ann. ^ Mag. N. Hist. Vol xii. L 



