Proceedings of Societies. 369 



the liver of a giraffe, and differed from all known species. Dr Cobbold 

 illustrated his paper with numerous drawings, showing the minute ana- 

 tomy of this worm and also several embryonic forms of entozoa- 



4. Mr P. A. Dassauville exhibited a specimen of the Gray Phalarope, 

 (Phalaropus lobatus), Lath., which was shot in the Firth of Forth in De- 

 cember last. The bird was only beginning to assume its winter plumage, 

 and appears to be a rare bird in this locality. 



5. Analysis of Datholite from Glen Farg. By M. Forster Heddle, M.D. 



Datholite, Dr Heddle said, has been found in the British islands in four 

 localities, all of these being Scottish — first, by Mr Rose, on the yellow 

 prehnite of Salisbury Crags ; then at Glen Farg, in Perthshire, asso- 

 ciated with zeolites, and well crystallized ; next, upon prehnite, in what 

 is mineralogically called the " Greenockite Hole," namely, the tunnel on 

 the Glasgow and Greenock Railway ; and, lastly, at Corstorphine Hill, 

 by Mr Forrest, within the last few years. It is a fact worth notice 

 that three out of these four are prehnite localities. This might warrant 

 a searching examination for boracic acid in prehnite. In all these locali- 

 ties the mineral has been recognised by its cry stallo graphic characters, no 

 analysis of a British specimen having yet been published. A specimen 

 from Glen Farg had been examined by Dr Heddle, and the analysis showed 

 nothing different from those made of foreign specimens, with the excep- 

 tion of '28 per cent, of oxide of iron ; and as a second analysis (made upon 

 crystals apparently absolutely pure) gave *24 per cent. Dr Heddle was 

 inclined to think that the iron is the colouring matter, giving the mineral 

 its light yellowish-green or asparagus stone tint. 



February 28, 1855. Robert Chambers, Esq., P. in the Chair. 



1. On the late Severe Frost. By Hugh Miller, Esq. 



Mr Miller remarked that the present intense frost, — coincident at new 

 moon with a stream tide,' — has killed many of the littoral shell-fish around 

 our shores ; and they now lie by thousands and tens of thousands along 

 thebeach. On the beach below Portobello, and for at least a mile on the 

 western side of the town, they are chiefly of two species, — Solen siliqua, 

 or the edible spout-fish or razor-fish, and Mactra stultorum, or the fool's 

 cockle, both of them molluscs, which burrow in the sands above the low- 

 water line of stream tides. The spout-fishes, when first thrown ashore, 

 were carried away by pail and basketfuls by the poorer people ; and yet 

 of .their shells enough remain in the space of half a mile to load several 

 carts ; but the fishes themselves, devoured by myriads of birds, chiefly 

 gulls, have already disappeared. The Mactra, though they may be picked 

 up in some places by basketfuls, are less abundant. It is probable, how- 

 ever, that both species will be less common on our coasts than heretofore, 

 for years to come ; and their wholesale destruction by a frost a few de- 

 grees more intense than is common in our climate, strikingly shows how 

 simply, by slight changes of climate induced by physical causes, whole 

 races of animals may become extinct. It exemplifies, too, how destruc- 

 tion may fall upon insulated species, while from some peculiarity of 

 habitat, or some hardiness of constitution, their cogeners escape. There 

 are two species of Solen in the Frith, 8. siliqua and S. ensis ; but we 

 have not seen, on the present occasion, a single dead individual of the lat- 

 ter species ; and, of at least four species of Mactra, Mactra stultorum 

 seems alone to have suffered. 



