792 CLASS XIII. 
Mantle with margin reflected, covering the circumference of shell. 
Tentacles thick, conical, bearing the eyes externally at the base. 
Sp. Parmophorus australis Buainv., Malacol. Pl. 48, fig. 2, Cuvier R. Ani., 
éd. ill., Moll. Pl. 65, &c. 
Emarginula Lam. Shell scutellato-conical, anteriorly emargi- 
nate. Mantle furnished with a single row of tentacles at the 
margin of foot, incised anteriorly, under the emarginate part of 
shell. Eyes set on tubercles at the base of tentacles. 
Comp. Cuvier Mém. sur les Mollusques, No. 18, pp. 14, 15, Pl. 1. figs. 
a= fi 
Sp. Emarg. fissura Lam., Patella fissura L., MUELLER Zool. Danic. Tab. 24, 
figs. 7—9. 
Of this genus, as of the preceding, fossil species are found. See La- 
MARCK Ann. du Mus. 1. pp. 383, 384; VI. Pl. xt. figs. 5, 6. 
Fissurella Brua. Shell clypeiform, with vertex perforate. 
Sides of foot margined by mantle, rugose, without tentacles. 
Mantle with an oval aperture on the back, corresponding to the 
perforation of the shell, leading to the branchial cavity. Anus 
placed below the fissure of mantle. Eyes sessile, placed externally 
at the base of tentacles. 
Cuvier Mollusq. 1. 1. pp. 12—14, Pl. 1. figs. 1, 2. 
Sp. Fissurella greca, Patella greca L., Buatnv. Malacol. Pl. 48, fig. 3, &e. 
This genus also is met with fossil; see Lamarck Ann. du Mus. 1. p. 312. 
The fossil species are principally from the tertiary formations, some from 
the Chalk-period. 
Haliotis LL. Shell depressed, auriform, with aperture very 
ample, spire very short. Head with two very long tentacles, and 
two oculiferous tubercles behind the tentacles. Branchial cavity 
placed to the left, including two lamellose pectinate branchie. 
Sub-genus Stomatia HELBLING, with addition of Stomatella Lam. 
Shell imperforate, with spire prominent. 
Sp. Haliotis imperforata Cummn., Gu., Stomatia phymotis HELBL., Mxus- 
CHEN Naturforscher, XVIII. 1782, pp. 19, 20, Tab. 11. fig. 18, Bnarnv. 
Malacol. Pl. 49 bis, fig. 4. 
Sub-genus: Haliotis Lam. Shell perforate by a row of foramina 
near the left margin, pearly within. 
Sea-ears. Feelers pass through the holes of the shell. These 
holes are closed up in the hinder part of the shell as the animal 
grows, and at the same time new ones are formed more forwards. 
