PHOS. 215 



Sub-Family PHOTIN^. 



(ienus PHOS, Montfurt. 



The animal of Fhos has a small head, with the tentacles ap- 

 proximating or connate at their base, and eyes near their tips ; 

 foot dilated, forming an auriculate, shield-like lobe in front, and 

 terminating behind in a long, tapering filament. 



The species of Fhos bear some resemblance to Nassa^ and 

 were originally placed in the famil}' Xassidsae ; from which, how- 

 ever, they are distinguished by certain good conchological and 

 malacological chai'acters. The turreted form, cancellated sur- 

 face and grooved interior of aperture are common to Nassa also, 

 but the oblique basal fold of the columella is characteristic of 

 this genus. The animal diffei's from Buccinum in the foot, 

 ending in a filament behind : Naasa has a bifid posterior termina- 

 tion. The genus is widely diff'used, the species however, as far 

 as known, being rather local in distribution. Phos has been 

 monographed b}^ Sowerby in Thesaurus Conchyliorum, Vol. III. 

 An inspection of his plates suggests the probable identity of 

 many of the species there figured as distinct. No allowance is 

 made by most describers for individual variation in form, sculp- 

 ture and coloring; 3'et. where a number of specimens of a species 

 from a single locality are compared, there will usually be found 

 to exist much ditterence in the number and prominence of ribs 

 and striie, coloring, etc. Even the angulated (or shouldered) 

 body whorl appears to be a variable character ; some specimens 

 of a single lot of P. Giiadaloupensis being broadly shouldered 

 as described ; others entireh- vv^ithout shoulder or angulation. I 

 am convinced that Miirch's subgenus Strongylocera, comprising 

 the species with angulated whorls has no title to distinction, and 

 I have suppressed it accordingl3\ I have allowed some species 

 to stand provisionally which, judging from the ascertained range 

 of variation in other forms, will probably event^^ially be con- 

 sidered s^'nonyms. 



^*.v. (Jrieibtal Hpeciea. 

 Ph. senticosus, Linn. PI. 83, figs. 479-490, 492, 493, 506, 575. 



White to chocolate brown, with or without yellowish or red- 

 dish brown bands. Length, 1-2 inches. 



Philippines ; New Caledonia ; Amboina ; Andaman Isles. 



