ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 323 
The fruit is sculptured with a network of raised ridges 
which thus produce depressions in the shell; this sculpture 
seems to have its seat in one of the caus membranes of the 
shell, 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 a diagramatic interpretation 
of what is supposed to be seen, rather than an actual repre- 
ihtation of fact. In the same way I have drawn the testa of 
Naias flewilis in fig. 85 from a single mature fruit in one of Dr. 
m more sure of c 
ae din 1* th uits h 
Italian N. alaganensis are granulose-punctate, we fairly well 
describes the € appearance of the outer covering of the Manchester 
ant; but Cesati’s figure in ‘Linnea,’ l. ¢., Table ii., fig. 2d, 
€ explanation of this difference in the form of sculpturing is 
probably due to the fact that the external membrane more or less 
observers according as the transparency of the outer layer admits 
of it. For the further elucidation of this point I have reproduced 
the figures of Dr. Magnus in Plate 252, where figs. 40 an show 
arrangment of the coats of the fruit of N. graminea from Cairo, 
and figs. 87 to 89 those of N. _ is. 
; i 
hundred plants which I have examined I have not seen a dine 
jmstance where the beak of the fruit was other than bifid, uwiless 
it had broken off altogether, as ee. in et 81 
i shonin pea 
: den A ‘ c “tsa mo xxxii., 1863, pages 259 and 260). 
