ETHER I A. 



Plate II. 



Species 2. (Mus. Cum. in Brit.) 



Etheria Cailliaudi. Eth. iestd foliared, irvegulari, 

 IcBvigatd, tulerculis spiniformihus tubi/e7'is, aliis ^ 

 extantibus, aliis decumbentibus armatd ; intus Jre- j 

 quenter vesicularis ; valvd inferiori nonnunqvam ' 

 profundd, concamrrata, area cardinali valdc 

 attenuatd. 



Cailliauu's Etheria. Shell foliaceous, irregular, 

 smooth, armed with spiniform tubiferous tubercles, [ 

 some outstanding, others decumbent; often vesi- i 

 cular within ; lower valve sometimes deep con- 

 camerated, with cardinal area very much 

 attenuated. 



Marcl 



Ferrussac. Mem. Soc. H. Nat., t. i. p. 150. 



Etheria tubifera, Sowerby. 



Hah. The River Nile, chiefly above the Cataracts. 



This species is of a lighter structure than the pre- 

 ceding ; there is a tendency to form blister-like 

 vesicles on the inner surface, and the substance of the 

 lower valve is chambered and deepened at the hinge, 

 which is sometimes, as seen in the specimen figured, 

 much prolonged. A specimen in the British Museum 

 is about eighteen inches in length, one third of the 

 length being occupied by the upper valve. 



, 1S72. 



