792 CLASS xin. 



Mantle with margin reflected, covering the circumference of shell. 

 Tentacles thick, conical, bearing the eyes externally at the base. 



Sp. Parmophorus australis BLAINV., Malacol. PI. 48, fig. 2, CUVIER R. Ani., 

 ed. 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 Mem. sur les Mollusques, No. 18, pp. 14, 15, PI. n. figs. 

 37- 



Sp. Emarg. fissura LAM., Patella fissura L., MUELLER Zool. Danic. Tab. 24, 

 figs. 79. 



Of this genus, as of the preceding, fossil species are found. See LA- 

 MARCK Ann. du Mus. I. pp. 383, 384 ; vi. PI. XLIII. figs. 5, 6. 



Fissurella BRUG. 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 Molhisq. 1. 1. pp. 12 14, PI. n. figs, i, 2. 

 Sp. Fissurella grceca, Patella grceca L., BLAINV. Malacol. PI. 48, fig. 3, &c. 



This genus also is met with fossil; see LAMARCK Ann. du Mus. I. p. 312. 

 The fossil species are principally from the tertiary formations, some from 

 the Chalk-period. 



Haliotis L. 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 branchiae. 



Sub-genus Stomatia HELBLING, with addition of Stomatella LAM. 

 Shell imperforate, with spire prominent. 



Sp. Haliotis imperforata CHEMN., GM., Stomatia pJiymotis HELBL., MEUS- 

 CHEN Naturforscher, xvm. 1782, pp. 19, 20, Tab. n. fig. 18, BLAINV. 

 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. 



