114 GASTEROPODA. 



recurved; inside with a chamber, and of a bluish or purple 

 colour. One inch long. Inhabits the American seas. 



Genus 16.— CALYFTRJEA.— Lamarck. 



Generic Character. — Animal oval or suborbicular, more 

 or less depressed, not spiral ; head broad, with distant lateral 

 tentacula, having the eyes on the middle of their outer bor- 

 der; foot nearly circular, very thin. Shell conical, base 

 orbicular, and summit vertical, imperforate, and acute ; in- 

 ternal cavity with a spiral septum. 



CalyptrcBa Sinensis. — The Chinese Calyptr^a. Plate 

 XIV. fig 19. Orbicular, subconic, smooth ; vertex ending 

 in a small volution ; margin entire ; cream-yellow ; very 

 glossy within, and provided with a laminar plate. Three- 

 fourths of an inch in diameter. Inhabits the Chinese seas. 



Genus 17.— PILEOPSIS.— ZawwrcA. 



Generic Character. — Animal with two conical tentacula, 

 and the eyes at their base externally; branchiae formed in 

 a row under the anterior margin of the cavity, near the 

 neck. Shell obliquely conical, anteriorly recurved, with 

 the apex curved and somewhat spiral ; aperture of a round- 

 ish oval; the anterior margin shortest, and the posterior 

 one large and rounded ; the muscular impression elongated, 

 arcuated, and transverse, situated under the posterior mar- 

 gin. 



Pileopsis Ungarica. — The Hungarian Pileopsis. Plate 

 XIV. fig. 31. Conical, vertex slightly spiral; longitudinally 

 striated, and transversely wrinkled; covered with a fawn- 

 coloured hairy or filamentous epidermis ; inside smooth, 

 glossy, white, or rose-colour. Two inches in diameter. 

 Inhabits the seas of Europe. 



Genus 18.— FISSURELLA. —Za?nareA. 



Generic Character. — Animal with the head truncated in 

 front ; two conical tentacula, with eyes at their exterior 



