322 MESSKS. HANCOCK AND ATTHEY 



are upwards of Atts of an inch in diameter, and nearly -i%ths 

 of an inch in thickness. Oval, depressed forms also occur, one 

 of which in our possession is iVths of an inch in length, though 

 one extremity is wanting, and i^o-ths of an inch wide. But by 

 far the gi'eater number are somewhat irregular in form, mostly 

 partaking, however, of the circle or ellipsis : one such elongated 

 specimen is an inch in length. Some have the margin a little 

 sinuous ; others are even pedunculate, or at least have a narrow 

 produced process at one end ; and it is not uncommon to find 

 them very much flattened, squeezed out as it were till the mar- 

 gins are quite sharp. The surface is invariably dull and much 

 like the matrix in texture, though in one or two instances we 

 have perceived indications of a reticulated structure. They leave 

 the matrix with great facility, frequently dropping out of it on 

 the shale being split open. 



When sections of these bodies are viewed by transmitted light, 

 they vary in colour from carmine to warm yellow, resembling 

 much in this respect fossil wood from the same locality, though 

 the latter is never so bright in tint. Like fossil wood, too, the 

 sections have a tendency to warp when placed on the slide, and 

 consequently the outer margin or rim is frequently cracked all 

 round on putting on the cover. 



That they are non-calcareous is proved by a very simple ex- 

 periment. If we place a fossil tooth or bone from the Newsham 

 shale in dilute nitric acid, a violent effervescence immediately 

 ensues, and the result is that in an hour or two the specimens 

 are either entirely broken down or are so much reduced that 

 they crumble to pieces on being touched with the finger ; hence 

 it is evident that such fossils from the above-mentioned locality 

 retain their calcareous matter not much, if at all, changed. Now 

 when we treat one of the lenticular bodies in question with nitric 

 acid of the same strength no action whatever takes place, and 

 after being immersed in it for several hours no perceptible effect 

 is produced. Fossil wood from Newsham shale is likewise un- 

 affected when subjected to the same influence. We have thus a 

 proof that these lenticular bodies are non-calcareous, and strong 



