Intelligence and Miscellaneous Articles, 241 



showed that in the non-carnivorous Cheiromys (Aye-Aye) sndPhas- 

 colarcius (Koala) a similar form of ramus obtains ; and that the 

 coronoid and condyle of the Aye-Aye are not unlike those of Plagi- 

 aulax, whilst in existing predaceous Marsupials the condyle has a 

 different form. The author is altogether confirmed in his opinion 

 that Plagiaulux was essentially a phytophagous marsupial. 



2. " On some Fossil Plants from the Hempstead Beds, Isle of Wight." 

 By the Rev. Dr. O. Heer, Professor of Botany, Zurich. With an In- 

 troduction, by W. Pengelly, Esq., F.G.S. 



These plant-remains, collected by Mr. H. Keeping, under Mr. 

 Pengelly's direction, from the Hempstead Series, consist of seeds, 

 cones, leaves, and twigs, and are referable to ten species, four of 

 which have been found lately at Bovey Tracey also, namely, Sequoia 

 Couttsice, Heer, Andromeda reticulata, Ettin., NymphcEa Doris, Heer, 

 and Carpolites Websteri, Brongn. The other species are Cyperites 

 Forbesi, sp. Tiox.,Nelumbium Buchii, Ettin., Carpolites globulus, sp. n., 

 Chora Esclieri, Braun, and Ch. tuberculata, Lyell, var. Professor 

 Heer notices that six of the above-named species are found also in 

 the Lower Miocene (Tongrian and Aquitanian) of the Continent, 

 and that this flora, as far as represented, seems to indicate truly 

 freshwater conditions for the formation in which it is found. 



3. " On Glacial Surface-markings on the Sandstone near Liver- 

 pool." By G. PI. Morton, Esq., F.G.S. 



The author here noticed the occurrence of glacial grooves and 

 scratches — 1st, at Toxteth Park, the direction of the striae being 

 N. 42 c W., at 120 feet above the sea ; 2nd and 3rd, at Boundary -lane 

 and New-road, Kirkdale, the stria? being N. 15° W., and at about 

 80 feet above the sea. 



XXXIII. Intelligence and Miscellaneous Articles. 



ON GROUND-ICE^ OR ANCHOR ICE. IN RIVERS. 

 BY PROEESSOR JAMES THOMSON. 



I"N this paper the author described the two principal modes of growth 

 -*- of ice, in still water and in running water. In still or slowly- 

 moving water the ice forms itself as a crust on the surface, because, 

 as the water cools from about 40° F. down to the freezing-point, it 

 expands, and therefore becomes lighter, and remains floating at the 

 surface, and then, on freezing there, it expands still further, and 

 therefore still more tends to float. In rapidly-moving river water, on 

 the contrary, and especially at the foot of rapids, ice is often found to 

 grow attaching itself to the rocks or stones forming the bed of the 

 river, as a spongy or porous mass, which, seen in the aggregate and 

 not examined minutely, presents a general appearance not unlike the 

 spawn of frogs. In large rivers in cold climates, as, for instance, in 

 the St. Lawrence, immense quantities of this ice, called ground- or 



