OF NAIAS GRAMINBA, VAR. DELILEI. 59 



which thus produce depressions in the shell ; this sculpture 



Fig. 8 1. 



Kg. 83. 



Pig. 82. 



seems to have its seat in one of the inner membranes of 

 the shelly since it cannot always be distinguished through 

 the most external layer. As far as I have been able to 

 make it out^ it is somewhat after the character of the 

 accompanying fig. 84; but this must be looked upon as 



Kg. 84. Fig. 85. 





m 







k^ 



a diagrammatic interpretation of what is supposed to be 

 seeUj rather than an actual representation of fact. In 

 the same way I have drawn the testa of Naias flexilis in 

 fig. 85 from a single mature fruit in one of Dr. Boswell's 

 Loch-Cluny specimens ; I am more sure of the correctness 

 of this figure than of that of N. grambiea, but it repre- 

 sents what is seen in a single fruit onlv. It would there- 



