95 



IRIDINA. 



Sowerbys Genera, No. 7, pl> 3. 



The G. Iridina so closely resembles the G. Anodon, 

 that it has only been separated from it in consequence 

 of the hinge being attenuated near the middle, and 

 having small tuberculated knobs irregularly distribut- 

 ed along its whole length, without any other appear- 

 ance of articulation. The substance of the shell is rather 

 thick and always more solid than the Anodon ; it has 

 a brilliant rose-colored pearly hue, the interior more 

 particularly iridescent; it inhabits the rivers of warm 

 countries. Shell equivalve, inequilateral, transverse, 

 with small apices, recurved but nearly erect; muscu- 

 lar impressions, similar to those of the Anodon : hinge 

 linear, attenuated near the middle, and its whole 

 length, appearing as if notched by frequent unequal 

 tuberculations; ligament external and marginal. 



An example of this very rare shell, which Sowerby 

 has figured and named Iridina elongata, is in the Pro- 

 vost of Eton's collection, and another in the late Earl 

 of Tankerville's cabinet. 



Iridina exotica. 



