OF CENTRAL CANADA PART IV. 221 



maple, oak, and other trees impressions of which occur in many 

 Post-Cainozoic clays, shell-marls, calcareons tufas, &c., as at Green's 

 Creek on the Ottawa, and elsewhere, at numerous localities, in both 

 Ontario and Quebec. 



ANIMAL REMAINS. 



The forms of the Animal Kingdom may be classed under nine 

 leading divisions or so-called sub-kingdoms, namely: 1. Protozoa; 



2. Polystomata ; 3. Ccelenterata ; 4. Echlnodermata ; 5. Vermes ; 

 6. Arthropoda; 7. Mollusca ; 8. Tunicata ; 9. Vertebrata. 



SUB-KINGDOM I. 

 PROTOZOA. 



This sub-division apart from a few fossil representatives com- 

 prises a number of minute, and in great part microscopic, types, 

 consisting of gelatinous sarcode-matter, destitute of true tissues and 

 special organs, and either naked, or protected by an external test or 

 shell of a horny, calcareous, or siliceous nature. Nearly all are 

 aquatic, but some few are internal parasites. They have no true 

 body-cavity, the sarcode-matter absorbing nutriment through its 

 entire substance, although in some of the higher forms (Infusoria) 

 certain portions of the body are more permeable than other parts 

 an approach towards an alimentary canal being thus indicated.* 

 The Protozoa admit of a sub-division into three natural groups : 

 Pseudopodifera, in which the body substance is extensible into long 

 or short pseudopodia (see preceding note) ; Gregarina, entozoic types, 

 pseudopodous only at an early stage of existence; and Ciliata, 

 including the ordinary infusorial forms, furnished with long or short 

 cilia, or, in one section, with retractile tubular suckers. 



Of these three groups, that of the Pseudopodifera alone presents 

 fossil representatives. This group includes four classes : 1 and 2, 

 Monera (?) and Amcebina, both soft-bodied and without fossil forms ; 



3. Forammifera, mostly with calcareous shell, and long, anastomos- 



* The amceba of our ponds and ditches will convey a good idea of a typical protozoan. 

 Under the microscope, this is seen to consist of a small gelatinous mass which possesses the 

 power of extending itself into short irregular projections, technically known as pseudopodia. 

 By the aid of these it moves along and captures passing infusoria or particles of nutriceous 

 matter, over which the body closes until digestion is effected. The creature thus improvises a 

 a temporary stomach. In actinophrys, a related form, often found in rain puddles, gutters, 

 &c., the pseudopodia are long and thin, and regularly radiated. 



