P. E. Raymond — Seaside Notes. Ill 



outside of the lateral ridges, averaged from 11 to 12 mm. 

 in width, except on firm sand, where it was 10 mm. The 

 shell of the animal which made it measured 10 mm. across 

 the aperture. There were six transverse bars in 33 mm. 

 Another trail was 14 mm. wide, 2.50 mm. deep, and had 

 14 transverse ridges in 80 mm. A good photograph by 

 Miss Dickerson of Littorina Utorea and its trails may be 

 seen in the American Museum Journal, vol. 16, p. 374, 

 1916. 



Lunatia heros is another gastropod which makes con- 

 spicuous trails on the sandy beaches. Being a large shell 

 it makes a broad track very similar to that of Littorina, 

 but with much more obscure transverse ridges. The 

 latter characteristic is probably due to the enormous size 

 of the foot. This animal is in the habit of burying itself 

 in the sand, and plowing along just beneath the surface. 

 A trail can often be seen ending abruptly, with a little 

 heap of sand at the end. Digging away the sand will 

 reveal the Lunatia just beneath the surface. Such mark- 

 ings remind one very much of Climacticnites, and support 

 Woodworth's contention that the famous Cambrian trail 

 was made by a large Mollusk. 2 Climacticnites is essen- 

 tially the same sort of trail as that made by Littorina, 

 and since the transverse ridges point forward in the 

 latter, Woodworth and Walcott were probably right in 

 their interpretations of the direction of motion of the 

 animal which made the former. The oval depressions 

 at the end of the trail of Climacticnites seem to me 

 not merely the place where it rested for a time. The 

 specimen from the Potsdam at Moers, N. Y., now in the 

 Museum of Comparative Zoology shows that the terminal 

 impression was not a simple one, but there are two or 

 three depressions at the end of each trail, all more or less 

 irregular, and in one case the sand is piled up at one end, 

 in another it has slumped at one side just as the sand 

 appears after a Lunatia has buried itself, 



The specimens of Climacticnites youngi figured by 

 Walcott 3 also support the interpretation as the trail of a 

 gastropod. These beautifully preserved specimens not 

 only show the forward-directed transverse ridges pro- 

 duced by the foot, but also a series of very regular, closely 



2 N. Y. State Mus., Bull. 69, 1903, p. 959. 



3 Smithson. Misel. Colls., 1912, vol. 57, p. 259, pi. 38, fig. 1, pi. 39, fig. 2. 



