428 Prof. J. Young and Mr. J. Young on 



The following are the localities in which portions of Hya- 

 lonema are found besides Cunningham Baidland : — Auchen- 

 skeoch, Dairy, in shale, rope abundant in 3 or 4 inch lengths, 

 spicules very rare ; Howrat Quarry, Dairy, in limestone, rope 

 only ; Dockra, Hillhead, and Trearne quarries, near Beith, in 

 limestone, rope; Wateidand Quarry, Dunlop, Ayrshire, in 

 weathered limestone, rope and spicules ; Brockley, Lesma- 

 hagow, in shale, rope ; Corrieburn, on the Campsie Hills, 

 in shale, rope; Bathgate, in limestone and shale, rope; 

 Chapel Quarry, near Kirkaldy, Fifeshire, in limestone on 

 nearly the same horizon, rope. Doubtless the rope is found 

 in many other districts, but the spicules, though found in 

 one or two places by the Geological Survey, have only been 

 got in abundance and good preservation in the Dairy district. 



2. Haplistion, nov. gen. (PI. XV. figs. 31-37.) 



General form massive, spheroidal, attached (?). Skeleton 

 composed of close-set similar fibres, which are collected into 

 more compact bundles, and end at the surface with truncated 

 extremities, between adjacent oscula or groups of oscula, this 

 arrangement giving the fossil a very rugose aspect. Oscula 

 numerous, inconspicuous, leading into canals which traverse 

 the mass without forming definite cellular planes. No ter- 

 minal aperture or internal cavity visible. 

 Species Haplistion Armstrongi, n. sp. 



Size. Length five eighths, breadth three eighths of an inch. 

 Locality. Cunningham Baidland. 



The three examples figured (the Only ones which we pos- 

 sessed last year), a fourth belonging to Mr. Armstrong im- 

 bedded in a cake-like flint nodule, and a fifth whicli we 

 believe identical, found at Arbigland by Mr. J. Thomson, are 

 the only specimens of whose existence we are aware. No 

 spicules have been recognized as belonging to the fossil, 

 though the teazed-out tissue lining the canals in fig, 34 has a 

 tantalizing suggestion of spicules about it. The curiously 

 parallel fibres^ which seem to be not spinulose, terminate in 

 the knobs (figs. 32, 33), so as to suggest the possibility of their 

 having once projected free from the surface like the whiskers 

 of Labaria. The sponge (figs. 31, 32, 33) is siliceous. 

 Figs. 34-37 represent two which have undergone the change 

 above referred to, having assumed a granular aspect, the 

 distinctness of the component parts being at the same time 

 impaired. It is not, therefore, absolutely certain that we 

 have to do with a siliceous sponge ; it may be that a horny 

 sponge like Dysidea has become silicified, as have tlie l)rachio- 



