UNIVALVES. 



PLATE LIL 



Genus. HALIOTIS. 



Character. Shell oval, ear-shaped, having on the back a row of spiracles, or 

 breathing holes, placed lengthwise ; the mouth pearly, and sinuated. 



Species. 

 No. 1. Haliotis rotundata. Shell brown, having a volute internally folded; 



the mouth pearly, green, red, and blue ; the spiracles circularly placed. 

 No. 2. Haliotis sinuata. Shell brown, slightly streaked with red, very much 



resembling the above, but more elongated in its form. 



Genus. AQUARIA, or WATERING-POT. 



Character. Shell spout-shaped, having at one end spiracles, or breathing-holes, 

 capable of pouring forth and receiving water; the body rounded in the form of a 

 pipe, and elongated ; the colour pale gray or brown. 



No. 3. Aquaria radiata. Shell gray, ornamented at the top by singular radii, 

 or spikes, projecting from a central knob ; the pillar banded irregularly- 

 This singular shell is a native of the South Seas, and has been much ad- 

 mired for the strange peculiarity of its shape, from which circumstance it 

 has derived its name. 



No. 4. Aquaria imbricata. Shell pale brown, tuberculous, having spiracles, 

 but not any radii. Native place unknown. 



Genus. ORTHOCERAS. 



Character. Shell turreted, elongated, having divisions or cells communicating in- 

 ternally with each other, the outside of the shell invested with longitudinal ribs of 

 the length of the shell, in the manner of the genus Scalaria. 



No. 1. Orthoceras scalaria. Shell brown, with white ribs, very pointed at the 

 lower end, and having a small spout at the upper part, opening externally. 

 This singular shell has chambers within. Found in the Baltic Sea. 



No. 2. Orthoceras decussata. Shell gray, having an ornamental fluting divided 

 by transverse bands or ligaments. Native place unknown. 



Genus. DENTALIA. 



Character. Shell tusk-shaped, pointed; the mouth round and wide, placed at one 

 end ; the body sometimes fluted, and ornamented with a few cross bands or ligaments. 



No. 3. Dentalia viridis. Shell green having longitudinal stripes, strongly in- 

 dented or raised from the body. A native of the South Seas. 



No. 4. Dentalia bandata. Shell of a pale brown colour, banded in the middle ; 

 the mouth small, and body very pointed at the extremity. 



No. 5. Dentalia denacta. Shell pale brown, having shortened longitudinal 

 flutes placed near to the mouth, and parallel to each other. A native of the 

 Eastern Ocean. 



