PHORUS. 8i 
PHASIANEL'LA. Auct. (Phasianus, a pheasant.) Fam. Tur- 
binacea, Lam. Ellipsostomata, Bl. Descr. Smooth, oval, varie- 
gated; aperture entire, oval; outer-lip thin; inner-lip thin, 
spread over a portion of the body whorl; columella smooth, 
rather thickened towards the base; operculum horny, spiral 
within; testaceous, incrassated without. Obs. The shells com- 
posing this genus are richly marked with lines and waves of 
various and delicate colours; and,if the genus be restricted to 
those species which are smooth, and which have a thick shelly 
operculum, we may regard it as well defined; but there are some 
spirally-grooved species of Turzo, Linn. which from their oval 
shape have been considered as belonging to this genus. Such 
species should not, in our opinion, be retained in this genus; 
they belong to Littorina. P. variegata, fig. 367. 
PHITIA. Gray. Carycuium, Miiller. 
PHOLADA’RIA. Lam. A family of the order Conchifera Dimy- 
aria, Lam. containing the genera Pholas and Gastrochena. To 
which may be added, Pholadomya and Galeomma. 
PHOLADOMY’A. Sow. (Pholas and Mya.) Fam. Pholadaria, 
Lam. Descr. Thin, rather hyaline, equivalve, inequilateral, 
ventricose, posteriorly gaping, elongated, anteriorly short, 
rounding ; ventral margin rather gaping; hinge with an elon- 
gated pit, and lateral plate in each valve; ligament external, 
short; muscular impressions two in each valve, rather indistinct; 
palleal impression with a large sinus. Obs. The only recent 
species of this genus is from the Island of Tortola. Several fossil 
species occur in rocks of the Oolitic series. Fig.57, P. candida. 
PHO'’LAS. Auct. (edo, pholeo, to lie hid in a cavity.) Fam. 
Pholadaria, Lam. Apssmacza, Bl. Descr. Transverse, oblong, 
equivalve, inequilateral, imbricated, gaping on both sides, the 
anterior hiatus being generally the largest, although sometimes 
nearly closed, with the dorsal margin surmounted with one or 
more laminar accessary valves; hinge callous, reflected, with a 
long curved tooth protruding from beneath the umbones in each 
valve. Obs. This genus of marine shells, dwelling in holes 
formed in rocks, wood, &c. is easily distinguished from any other 
nearly approaching genus by the curved, prominent, rib-like 
tooth. Fig.55, Pholas Dactylus; 56, P. papyracea. 
PHOLEO'BIUS. Leach. Part of the genus Saxicava, Auct. 
PHOLADIDAYA. Leach. PuHotas papyracea, Auct. fig. 56, 
Remarkable for the cup-shaped process at the posterior ex- 
tremity. 
PHONE’MUS. Montf. A genus of microscopic Foraminifera. 
PHORUS. Montf. Trocuus agglutinans, Auct. Fig. 360. Re- 
markable for the adhesion of little pebbles, dead shells, &c. to 
the outer edge of the whorls which are taken up in the course of 
the growth of the shell. From this circumstance they are called 
* Collectors.”’ M 
