MYTILlDiE, 
377 
° n chial syphon. The other, serving the purpose of ejecting the 
Products of digestion, is termed the anal tube. The tentacles of the 
°uchial tube seem to he possessed of exquisite sensibility. When 
Pig. 165. Douux rugosiis (Linnauis). 
Pig* 166. Donax denticulatus. 
'lehed, the animal draws in its syphon, and only puts it forth anew 
tn the danger has passed. The species of Donax are very nume- 
r ° u s, especially in the Asiatic and American seas. Among the European 
®P 6 cies we may mention Donax rugoms (Fig. 1 (55) and Donax den- 
tins (Fig. 166). 
Fig. 167. TeLLIoa radial a (Linnaeus). 
^ext to Donax naturalists rank the genus TelUna, which includes 
ll >auy S p ec [ eg 0 f very minute 
I l( ^H all remarkable for their 
^ eaut y of form, and for their 
^hant and varied colours, 
of these, called the Rising 
(TelUna radiata ), is repre- 
^ted i n p ig 1 67i Tlle Tellinas 
4 e Lund in every sea ; the French coast furnishes many species : 
Xat Uples, TelUna, virgata (Fig. 168) and Tellina sulphurea (Lamarck) 
