334 MOLLUSCA. 
ANIMAL with the foot elongated oval, ochreous yellow; margin yel- 
lowish, becoming purplish at the outer edge; branchie surrounding 
the foot; head semi-oval, dilating posteriorly, appearing distinctly 
hooded below. 
Figure 427, under side of the animal. 
PATELLA TALcosa (Gould). 
‘esta magna, solida, ponderosa, rotundata, depressa, costulis radiantibus 
numerosis subequalibus rotundatis flexuosts instructa, vertice sub-cen- 
trali, colore saturate cinnamomed ; facies interna talcoso-argentata, 
purpureo tincta ; callo central crasso, albo, spatuleformt, ad marginem 
radiato ; impressione musculart lato, profundo : margo crenulatus. 
Patella talcosa, Gout; Proceed. Boston Soc. Nat. Hist., ii. 148. 
July 1846. Expedition Shells, 6. 
A large, ponderous, depressed, dome-shaped shell, the apex nearly 
central, covered with numerous small, nearly equal, rounded, flexuous, 
radiating ribs. Colour a deep cinnamon-brown; the interior has a 
light, silvery, mother-of-pearl lustre, with crimson reflections where the 
shell is thin, and with the unctuous feel of tale ; the centre is occupied 
by a very thick, white, tongue-shaped callus, radiately dentate at its 
margin. Muscular impression very broad, very deeply impressed, 
and double. Edge slightly crenulated by the ribs. 
Length four inches; breadth three and a half inches; height an 
inch and three-fourths. 
Inhabits Hawaii, Sandwich Islands. 
The colours of the interior, in small specimens, are very rich, and 
the shell is of a rounded, shield-like form, like P. testudinaria, attain- 
ing sometimes a very large size, larger than any other species except 
P. pyramidata. It seems to be somewhat common in collections, but 
I cannot identify it with any published description. 
Figures 452, 452 a, 452 d, three views of the shell. 
