Manchester Memoirs, Vol. xliii. (1899), No. 1. 11 



The " oval-shaped head " is figured as a depression 

 against which the cast abruptly stops. It looks like, and 

 probably is, a worm-burrow. 



Chondrites inforniis McCoy. {Plate \, figs. 8, 9, 10.) 



Among the worm-casts collected by Mr. Lamplugh 

 in the course of his examination of the slates there is a 

 series dififering from any hitherto described, and of larger 

 size. By his kindness I have been enabled to examine them. 



The castings vary in size from a diameter of three to 

 seven lines. They are composed of rather coarse grains 

 of sand, which are partially compacted together. The 

 matrix upon which they lie, often in high relief, is a 

 slaty grit. A few of the castings are solitary, and when 

 well preserved show a gradual reduction in diameter 

 towards one extremity. More often they occur in clusters, 

 lying parallel to or overlapping one another. Where 

 they overlap, subsequent crushing has obliterated, to 

 some extent, the lines of apposition between contiguous 

 castings, so that they appear at first sight as branching or 

 forked structures. 



Their resemblance to Chondrites informis McCoy, is 

 so very close that we include them in this species. 



Crustacea are represented by the impression of a 

 single obscure trilobite. Doubt* has been expressed as to 

 this impression being that of a trilobite, but the balance 

 of opinion is strongly in its favour. 



u^glina or A saphus. {Plate i, fig. 12.) 



The trilobite impression found at Ballastowell has 

 been already referred to. It will be sufficient if we now 

 give a diagnosis, already published in the Geological 

 Magazine. 



* G. W. Lamplugh. "The Crush Conglomerates of the Isle of Man." 

 Quart, lotirn. Geol. Soc, Vol. li., 1895, p. 578. 



