ZoQioyical Society. 147 



lineolatd, et maculis Unearibus luteis subseriatis pictd ; apice sub- 

 violascente ; labio triangulari, antice arcualim excavato. 

 Var, ^. T. elongatd, lateribus compressd, dorso convexo-fornicatd, 

 antice subacute, interdum truncato ; luteo-fuscescentCy maculis ob- 

 longis antice ?iigris acutis laieraliter lineolis tenuissimis obsoletis- 

 que obumbratis pictd; apice ititerdmn nigrescente, labio triangu- 

 lari, luteo-fuscescente> 

 Var. e. T. oblongo-ellipticd, lateribus compressd, lineolis pallide 

 fuscis aut purpurascentibus, et maculis oblongo-conicis luteis pictd ; 

 radiis binis, pallide luteis in medio dor si notatd ; labio triangulari, 

 antice arcuato. 

 Var. a : long. 0'88 ad I'OS ; lat. 0*44 ad 0*56 ; conv. 0*24 ad 0'48 

 poll. Var. /3 and y : long. 0-96 ad 1*04 ; lat. 0*60 ad 0-64 ; conv. 

 0-32 ad 0-36. Var. Z : long. 052 ad 064 ; lat. 0*32; conv. 0-28 

 ad 0-32. 



Hab. Var. o, from Banguey, province of North Ylocos : on stones 

 in a mountain-stream. Var. /3, from Cagayan : on stones in a large 

 river. Var. Z, from Baccara : on stones in a rapid river. Var. e. ? , 

 cum praecedenti. 



All these varieties are very remarkable, and, with the exception 

 of var. e, whose operculum I have not seen, all certainly belong to 

 the same species. The operculum of Nav. lineata is oblong, very 

 thin, pale yellow, a little inclined to pale green, rounded behind, 

 notched before, notch in an oblique line at the base. The left side 

 of this operculum is slightly arcuated in the centre ; the right side 

 almost rectilinear and limited by an apophysary tooth, very narrow 

 and a little prolonged anteriorly. Muscular impression triangular, 

 elongated, inclined obliquely to the left. 



9. Navicella Entrecastauxi, Recluz. Rev. Cuvier. p. 380, 

 No. 14. 



Var. /3. T. obovatd, nigro-purpurascente, concenirice et crebre lineo- 

 latd, maculis luteis conicis aut subquadratis pictd ; apice purpura- 

 scente marginali, non exserto ; aperturd albido-cterulescente. 

 Long. 0-80 ad 0-90 ; lat. 0-56 ad 0*60; conv. 0*20 ad 0-28 poll. 

 Hab. ad insulas Philippinas. 



Operculum almost square, of the form and sculpture of that of 

 Nav. tessellata, offering however some characters which the state 

 of that which was submitted to me does not allow me to judge of 

 with certainty. Its colour is of a rosy white, and yellow in the cen- 

 tre. It is possible that the N. Entrecastauxi may prove only an 

 oboval variety, with a marginal summit of N. tessellata. When I 

 shall have seen a greater number of specimens with their opercula 

 I may be enabled to pronounce with more certainty. 



It results from this examination of the Navicellce collected by Mr. 

 Cuming, together with those I have had an opportunity of studying 

 up to the present time — 1st, that the number of known species of 

 this genus amounts at present to eighteen ; 2ndly, that the Asiatic 

 Islands is that part of the world which contains the greater number 

 of species; and 3rdly, that Polynesia is afterwards the most rich 

 locality in species of this genus. 



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