146 DITBLIW NATTTEA^L H18T0EY SOCIETY. 



excavations distinct one from the other, with sharp-cut edges, and evi- 

 dently but recently formed by cutting, and not due to the mere growing 

 up of any organism to the edges of a system of cells. These excava- 

 tions were cut out of a brown substance, which swelled up on the appli- 

 cation of the water, and under a high power of the microscope resolved 

 itself into filaments of oscillatoria or some allied alga. 



The same objections, especially the fii'st quoted, applied to another 

 opinion, and one which at first sight seemed not improbable, viz., that 

 the markings might be sun-pictures on the slate rocks of zoophytes, or 

 algaa. 



Mr. Du Noyer suggested the idea that they were in some way con- 

 nected with the tracings formed by molluscs in the act of feeding. To 

 this opinion there appeared only one objection, viz., the plumose cha- 

 racters oi* the markings exhibited ; the ordinary track of a molluscan 

 tongue being either perpendicular to the transverse plane of the animal's 

 body, or else a long winding track ; sometimes, it is true, a series of 

 curves, but these curves disjointed from one another, and in no degree 

 plumose. 



Some tracings of Patella vulgaris, which I obtained at Lough 

 Shinny, have, however, explained the whole matter. In these we see 

 the ordinary perpendicular markings gradually passing into a zigzag 

 line, and then into a series of connected but separate curves, which 

 gradually approximate one to the other, till at length at the extremity 

 of the animal's feeding ground they overlap and form a series of plu- 

 mose tracings precisely similar to the markings on the specimens of slate 

 rock communicated to me by Mr. W. H. Baily. 



I have been induced to bring this before your Society on account of 

 the great mischief which, it appears to me, the general apathy of zoolo- 

 gists on such subjects has caused in the rational study of zoology, such 

 things as tracks being generally considered too insignificant to engage 

 the attention of the student, whilst in truth many palseontological 

 puzzles might have much light thrown on them if zoologists did their 

 duty in living ichnology. I have been so much impressed by this, that 

 for some time past I have been making a series of observations on this 

 point, and have arrived at some very curious results ; and although se- 

 veral of these have been anticipated within the past few months by the 

 interesting observations of Mr. Albany Handcock in the '' Annals of 

 Natural History," yet there remains still a great deal to be done in this 

 field, especially as regards the tracks of the star-fishes, the tubicolous 

 and wandering worms, and the bivalve molluscs, all of which, I find, 

 make most peculiar and interesting traces. 



It is indeed a just cause of reproach to naturalists studying living 

 forms, that, when appealed to by the palaeontologist as to the probable 

 origin of animal traces met fossilized, in ninety-nine cases out of a hun- 

 dred no definite information can be given, because, fotsooth, animal 

 traces are too trivial a subject to devote time to ; although these traces, 

 if properly studied, afi'ord much and valuable information as to animals' 

 habits, and the conditions under which the animals lived and died. 



