44 
had not changed its situation, from an early stage ot 
growth I have also obtained it, of small size, from th e 
stomach of a fish. 
* P. MILITARIS. Patella M. Mont. Test, Brit., vol. 2, 
p. 488, pi. 13, fig. 11. Capulus M. Flem. Brit. An. p. 364. 
At various parts of the coast, but scarce. 
P. ANTIQUATUS ? Montagu describes this shell (Patella 
Antiquata) as liable to great variation ; under which it 13 
not improbable that more than one species is included' 
My specimen, which was attached to a Pinna, was abo llt 
aline in its longest diameter; texture thin, and in pan 5 
nearly transparent: longitudinal lines from the point to th 6 
margin simple, causing the edge to be angular ; crossed uj 
their progress by circular ridges, seven in number, incline 11 
towards the margin. Curve of the cap to the right, as th 0 
broad expanse is placed forward : its form much as in P • 
Hungarica, but more bent down. Colour pale yellow. 
CALYPTRiEA. 
GENERIC CHARACTER: The shell conoidal, sum®' 1 
erect, imperforate, subacute. Cavity furnished with alJ 
attached, convolute plate. 
C. SINENSIS. Patella S, Turt. Lin. P. Chinensis- 
Mont. Test. Brit., vol. 2, p. 489, pi. 13, fig. 4. C. <> 
Flem. Brit. An., p. 362. Found on oysters at Helford. 
and generally wherever native oysters are dredged ; bu 
soon falling off spontaneously, it escapes observation. 
ANCYLUS. 
GENERIC CHARACTER: The shell ovate, conica'- 
sitnple, the tip central, posterior, rather obliquely r6 ' 
curved to the right; cavity with a lunate submarginal scab 
interrupted on the left side. This genus is by 
classed with the Limnaeadae, on account of the form oi tl1 
animal inhabitant. The shell, continues Mr. Gray, if° 
whom the generic character is derived, differs t r0 
Siphonaria, with which alone it can be conlounded, ® 
account of the peculiar form of the muscular scar, and 
lateral situation of the apex ; in being thin and pelluc' 1 ' 
only finely striated and covered with a thin olive p crl °j 
traca. It only agrees with Patella in the out' faf j S 
appearance of the shell, for in that genus the ape* 
anterior, and in this it is posterior, as in most univalves. 
•A. FLUVIATILIS, Patella F. Mont. Test. Brit., vdb *' 
p. 482. Flem. Brit. An., p. 280. Gray’s Turton’s Manna » 
p. 249, pi. 10, fig. 125. Common on stones, in rivulets. 
BULL2EANA. 
Either without a shell; or the shell without colunie ^ 
or projecting spire ; inflated ; aperture large, the length 
the shell. 
