31 



ON SOME 'FEEDING-TRACKS' OF GASTROPODS. 



By B, B. Woodward, F.L.S. 



Read Sth December, 1905. 



Some time since, Mr. W. J. Lewis Abbott, of St. Leonards-on-Sea, 



sent me a spoilt bromide print of a photograph on which a Gastropod, 



t evidently a slug, had not only crawled, leaving the usual shining trail 



as it passed, but had fed on the gelatinous surface by the way. 



r On the black, over-exposed portions of the print, where the animal 



( had browsed, it had eaten right through the surface to the white paper 



>; below, thus causing the pattern of the 'feeding-track' to stand out 



very distinctly (Fig. 1). 



Fig. 1. 



This pattern, formed as the animal moved its head from side to side, 

 in an arc, whilst feeding, looks like some picture of a branching- 

 Madrepore, each apparent calyx being the result of a single lick. 

 These licks are roughly, but not regularly disposed in curved rows 

 across the line of advance. In shape each lick, of which there were 

 about 12 to 18 in each row, rudely resembles an inverted V. 



When highly magnified, a yet more interesting feature becomes 

 apparent, for each lick is resolved into a number of some 16 or 



