THE FAMILY NAIADES. 



151 



Not being able satisfactorily to make out 

 or arrange the following species, I have 

 deemed it best simply to insert a list, in their 

 order of habitat. 



EUROPE. 



Unio rubens. Menke. 

 Unio rugatus. Menke. 

 Unio gibbus.f Speng. 

 Unio truncatus.f Speng. 



ASIA. 

 Unio orien talis. Fer. 



AFRICA. 



Unio Juliani. Rang. 



NORTH AMERICA. 



Unio Groenlandicus.f SchrO. 

 Unio purpuriatus. Say. 

 Unio oviformis. Con. 

 Unio furvus. Con. 



SOUTH AMERICA. 



Unio nitidens. Fer. 

 Unio obtusus. Fer. 

 Unio preciosus. Fer. 

 Unio psammoica. D' Orb. 

 Unio rhuacoica. D''Orb. 

 Unio Foniainiana. D'Orh. 

 Uniohylaea. VOrh. 

 Unio Guaraniana. D'Orh. 



HABITAT UNKNOWN. 



Unio pulchellus. Fer. 

 Unio musivus.f Speng. 



The following Fossil species have been 

 observed in Great Britain : — 



Unio crassiusculus. Sow. 

 Unio concinnus. Sow. 

 Unio uniformis. Sow. 

 Unio acutus. Sow. 

 Unio Listeri. Sow. 

 Unio Solandri. Sow. 

 Unio porrectus. Sow. 

 Unio compressus. Sow. 

 Unio antiquus. Sow, 

 Unio aduncus. Sow. 

 Unio cordiformis. Sow. 

 Unio crassissimus. Sow. 

 Unio subconstrictus. Sow. 

 Unio hybridus. Sow. 

 Unio Urii. Flem. 

 Unio abductus. Phil. 

 Unio peregriuus. Phil. 



The following have been observed in the 

 United States: 



Unio petrosus. Mort. 

 Unio tumulatis. JVLort. 

 Unio terrenus. Mort. 

 Unio saxulura, Mort. 



t On the authority of Ferussac. 



