Vol. 68.] 



IN THE PERMIAN ROCKS OF HAMSTBAD. 



677 



(5) Impressions other than Tracks or Footprints. 

 These include a cast in relief of a fish. 



insect-wing, and casts of entomostraca (?). 



the impression of an 

 None of these show 

 any trace of the organic substance of the fossil, and are all badly 

 preserved. 



The insect- wing occurs on the surface of a slab of red sand- 

 stone, wliich shows also some well-preserved rain-prints and a 

 pair of casts of amphibian footprints. The wing, which is incom- 

 plete at the proximal end, measures 5'3 cms. in length, and 2 cms. 



Fig. '30. — Insect-winy (1), etc. from Hamstead 

 (half of the natural size). 



in breadth. As one cannot be absolutely certain of the organic 

 origin of the marking, I merely give a figure of the specimen 

 (fig. 30). On the same slab, near the first, is a second marking 

 of somewhat similar character, and disconnected from it. The 

 ' nervures ' in this marking are almost obliterated. 



The markings interpreted as entomostracan casts are usually 

 found on the nether surfaces of bods of sandstone, in what were 

 once hollows of the underlying beds. The casts are concave on the 

 one side, convex on the other, aud have rounded ends. The length 

 of one type is 1 mm., and its breadth 0*2 mm. Others are 2 mm. 

 long and 1 mm. broad. 



