196 Proceedings of Royal Society of Edinhirgh. [march 5, 
wliicli takes charge of the particles. The way in which the outer 
palp does its share of the work is rather ingenious. It is curved 
round the anterior end of the gills on its own side, its outer margin 
parallel with theirs, and its outer convex surface sloping away to 
the mantle-lobe. Any material brought along the free margin of 
the gill is quickly transferred along the convex outer surface of the 
palp, thence along the lower (inner) margin towards the tip, and 
finally handed over to the muscular margin to he conveyed out of 
the body. The outer palp sometimes appears to carry away material 
brought by the inner gill, and these particles sooner or later are 
passed to the muscular margins of the mantle-lobes, whence they are 
rapidly conveyed outside. The mantle-lobes and the foot also drive 
out foreign particles from the posterior end of the body by means 
of their cilia. 
Huxley, in his Anat. of Invert. Animals^ says: — “ The same agency 
[^.e., the ciliary currents created by the gills] bring the nutritive 
matters suspended in the water within reach of the labial palpi, hy 
tvhich they are guided to the mouth.’’’ 
Lankester, in his article “ Mollusca,” already referred to, says: — 
“ The food of the Anodon, as of other Lamellibranchs, consists of 
microscopic animal and vegetable organisms, which are brought to 
the mouth by the stream, which sets into the subpallial chamber 
at the lower sephonal notch. Probably the straining of water from 
solid particles is effected by the lattice-work of the ctenidia or gill- 
plates.” 
And Keferstein* says : — “ Organic particles in the water-stream 
are driven along the free margin of the gills and forwards between 
the mouth-lobes, where the position and movements of the latter 
convey them into the mouth.” But he immediately afterwards 
adds, “ the mouth, in an unknown manner., appropriates the solid 
particles.” 
Claus, in his Zoology (English translation), vol. ii. p. 17, says : — 
“ Food materials pass with the water to the labial palps and so to the 
mouth;” and at p. 21— “The mouth leads into a short oesophagus, 
into which the cilia of the labial palps drive small nutritive particles 
received into the mouth-cavity with the water.” 
How, unfortunately for these statements, the cilia of the palps. 
Bronn’s Thierreichs, vol. iii. p. 415. 
