﻿ON THE TRACKS OF INSECTS RESEMBLING THE IM- 

 PRESSIONS OF PLANTS, 



By M. R. Zeiller.* Translated from the French, by 



Joseph F. James, 



Custodian Cincinnati Society of Natural History. 



In his important memoir upon "Some Tracks of Invertebrate 

 Animals," M. Nathorst mentions the tracks formed on the surface 

 of clay soil by some animals, "that, immediately under the surface, 

 give rise to cylindrical tubes or tunnels, parallel with the surface." 

 He described principally, a track found by him on a clay road, 

 "and with the same structure as that of Phymatoderma the 

 unknown animal that had produced this, "having crawled under the 

 surface of the mud, had forced into relief a great number of little 

 rounded points, " which produced a resemblance to those observed 

 in this genus by Schimper, and compared by him to the papilli- 

 form excrescences of some CaulerpaA 



I have observed during the past summer near Villers-on-the-Sea, 

 the tracks of this same genus, and have been struck with their re- 

 semblance to certain impressions of fossil plants. These tracks 

 were found on the bottom of a little pool of water, which was 

 sometimes nearly dry, aud was situated on one of the flat spaces 

 formed on a steep part of the coast by the sliding of the marls of 

 Oxford (marls of Villers). They were produced by an animal 

 that had excavated galleries, .015 m. (6-10 of an inch) in diameter, 

 and sunk to a depth of .005 m. (2- 10 of an inch) below the surface, 

 and parallel to it. The clay soil had been elevated into the form 

 of a half cylindical ellipse, the upper surface of which was covered 

 along its whole length with these rounded, blunt points. These 

 sometimes assumed a very regular spiral arrangement, and at 

 others were arranged in two parallel, longitudinal series, separated 

 by a middle ridge. To give more clearly to these tracks the appear- 

 ance of the impressions of plants, they branch quite frequently ; 

 one series of galleries starting out at right angles, sometimes to 



*From the Bulletin de la Societe Geologique de France, 3d Series, Vol. XII., p. 676, 

 et seq. 



t A genus of sea-weeds. Q.] 



