!{30pul;ir iDtcttonarn of Sufmatrtf 



347 



INCA. A genus of Lamellicorn Beetles, 

 by many authors placed among the Goliath 

 beetles, but whose situation in the system, 

 according to more modern views, is nearer 

 TricMus. They are natives of South Ame- 

 rica. The species figured here is Inca V.'cbcri. 

 It is of a violet black ; the thorax edged 

 with white ; three-banded, the outer bands 

 connected with the white edge of the thorax: 

 the elytra have a reddish tinge, spotted with 



! small palish marks. It is a native of South 

 America : and the accompanying figure 

 will show its form and appearance. [See 

 GOLIATH.] 



INDICATOR. [See HONEY-GUIDE.] 

 INDRI. The name of a quadruped be- 

 longing to the family Lemuridie. It is a 

 native of Madagascar, and from its fine long 

 hair is called Indris laniyer. 



INFEROBRANCHIATA. An order of 

 molluscous animals (Gasteropods), charac- 

 terized by the position of the gills, which 

 are situated beneath the produced margin of 

 the mantle. They are incapable of swim- 

 ming, and are therefore confined to the sea- 

 shore, where they subsist upon sea-weeds 

 and other aquatic plants. 



INFUSORIA. A term applied by na- 

 turalists to the numerous minute animals 

 found in water, which are commonly called 

 animalcules. Had the microscope never 

 been invented, the existence of myriads of 

 living creatures whose forms aud properties 

 are now in some measure revealed to us, 

 would have been wholly unknown. Ehren- 

 berg, who by means of a most powerful mi- 

 croscope, was enabled to describe species 

 which are not larger than from one-thou- 

 sandth to two-thousandth of a line in dia- 

 meter, infers, that a single drop of water 

 may hold 500 millions of these animalcule. 

 By what arithmetical power, then, shall the 

 numbers that swarm in every stagnant pool 

 or lake be calculated ? " All true Infusoria," 

 says he, "even the smallest monads, are 

 organized animal bodies (none consisting of 



a homogeneous jelly), and distinctly pro- 

 vided with at least a mouth and internal 

 nutritive apparatus." They are found 

 equally abundant as fossils. The Norwegian 

 earth, called BeargrneM, or Mountain meal, 

 is principally composed of fossil animalcules. 

 Professor Bailey tells us that the town of 

 Charleston, in the United States, is built 

 upon a bed of auimalculae several hundred 

 feet in thickness, every cubic inch of which 

 is filled with myriads of perfectly preserved 

 microscopic shells. He says also, that these 

 polythalamia, or many-chambered shells, to 

 whose labour South Carolina owes so large a 

 portion of her territory, are still at work, in 

 countless thousands, upon her coasts, filling 

 up harbours, forming shoals, and depositing 

 their shells to record the present state of the 

 sea-shore, as their predecessors, now en- 

 tombed beneath Charleston, have done with 

 regard to ancient oceans. The most highly 

 organized Infusoria are called by Cuvier 

 Rotifera [which see]. 



The immense importance of the Infusoria 

 in the scale of animal existence is chiefly 

 seen by those who visit the Arctic and Ant- 

 arctic seas. Although remotely supporting 

 the higher animals, yet the want of them 

 would be materially felt. This is well stated 

 by Capt. Sir James Clark Ross, who, in 

 speaking of a small fish found by him in the 

 South Seas, and described by Dr. Sir John 

 Richardson, under the name of Notothenia 

 phucce, says, " They occupy the place of the 

 Merlanffiis poJaris and Ophulium Parryii, of 

 the Arctic seas, the latter of which they 

 much resemble ; like them, they conceal 

 themselves from the persecutions of their 

 enemies in the small cracks and cavities of 

 the pack ice, and may be seen when driven 

 from shelter by the ships striking and pass- 

 ing over their protecting pieces of ice. The 

 seals and petrels are their chief enemies, 

 whilst they, in their turn, live upon the 

 smaller Canci-i and Limacince. Thus we be- 

 hold in these regions, where the vegetable 

 kingdom, which constitutes the support of 

 animal life in milder climates, has no repre- 

 sentative, a chain of animal existences, 

 maintained by each preying upon that next 

 below it in the order of created beings, and 

 all eventually nourished and sustained by 

 the minute infusorial animalculae which we 

 found filling the ocean with an inconceivable 

 multitude of the minutest forms of organic 

 life." Antarctic Voyage, vol. ii. p. 161. 



INSECTS. (Insccta.') A class of inver- 

 tebrate animals, to which the term insecta 

 has been applied, in reference to the in- 

 sected, or divided, appearance of the body, 

 which is not only composed of a continuous 

 series of segments, articulating with each 

 other, but is also often divided or cut into 

 three very marked portions, to which the 

 names head, thorax, and abdomen have been 

 applied. There is no class of the animal 

 kingdom which has been the subject of more 

 numerous and various attempts at classifica- 

 tion than that of Insects : nor is it at all 

 surprising ; since it is pre-eminent in regard 

 to the number of distinct species which it 

 includes, and unsurpassed by any, save the 



