REVIEWS. 



539 



were, Pterinea, Grihonota, 2'nncula, Avicula, Orthoceras, Eurypterus spinipcs, 

 E. clavipes. 



To the liora of the Forfarshire beds he had added several new and gigantic fiicoids, 

 a Lepidodendroid stem, and a fern [Cyclopteris) ; to the fauna, gigantic worm-tubes 

 (Scolithus), annelidan tracks, and the remains apparently of an annelide itself, 

 and two crustaceans, described and figured by himself under the generic names 

 of Kampecaris and Slylonurus. A considerable number of ichtliyodorulites had 

 been discovered, and were as yet undcscribed. To a small fish with a kitc-sli.iped 

 head and shagreen-like scales, armed with fin-spines, he had given the name of 

 Ictinocephalus granulatus. 



Specimens had also been obtained throwing additional light on the nature of 

 previously partially known and obscure fossil organisms ; thus we now possess 

 a knowledge of the corneous eye-capsule, the pectoral and dorsal fins, and the 

 true form of the great heterocercal tail of the Cephalaapis^ and we could now 

 restore it as a not inelegant fish, resembling in general contour the Aspidophorus, 

 or armed "bull-head " of our coasts. 



Mr. Page acknowledged his obligations to the labours of Mr. Powrie, of Res- 

 wallie, and to Mi*. Slimon, of Lesmahagow, for the discovery and preservation of 

 many of these new fossil forms. 



EEVIEWS. 



The Canadian Journal. September, 1858. 

 Amongst the other very nice articles in this number is one by Mr. Dumble, the 

 engineer of the Cobourg and Peterborough Railway, on some natural phenomena 

 of the expansion and contraction of ice by variations of temperature. In a 

 territory like Canada, there are advantages, from climate and other causes, of 

 studying on the grand scale the phenomena of ice and the effects of the congelation 

 of large masses of water which we never possess in England ; and many results 

 are thus visible there, which, on the diminutive scale on which such natural opera 

 tions occur in our island would be nearly inappreciable. 



The mere facts that ice floats upon water and that vessels of any description , 

 which contain water, fracture and burst from its congealing, are proofs suflQciently 

 practical and familiar of the increase of its bulk by crystallization ; but that ico 

 itself should be capable of expanding and increasing in bulk is not equally well 

 known, although many practical proofs are afforded. This property of expansion 

 and contraction of ice aids in fracturing and reducing the gigantic iceberg ; and 

 but for these changes, from variations of temperature far below the freezing point, 

 causing pressure, collapse, fracture, and disruption, the short Arctic summer 

 would fail to open the Arctic seas. The phenomena recorded by Mr. Dumble are 

 those occurring on Rice Lake, across which the Cobourg and Peterborough Rail- 

 way is carried on a pile- and truss-bridge of timber. This bridge, on more southern 

 waters, would have been considered a most suitable structure ; but, owing to the 

 almost irresistible expansive force of the ice, now presents the ai^pearanco of a 

 complete wreck. The violent movemoiit of ice on this lake is entirely due to 

 contraction and expansion, solelj? from changes of temperature. The lake generally 



takes" with ice during the month of December at a high- water level, which high 

 level the dam across the outlet preserves until spring, and the movements of the 

 ice are therefore divested of the influence of currents, nor are they subject to those 

 other various causes, such as the diff"ering temperatures of ice and sea-water, or 

 v.'ave action. 



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