230 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



once plainly overarched by gneiss, and that it is foliated, 

 there being a regular succession of leaf-like layers from the 

 walls toward the centres of the cavities, witness to which is 

 borne by a like succession of different minerals; that in some 

 places it ramifies through the surrounding rock in a vein-like 

 way, while in others it exactly conforms with the most ab- 

 rupt irregularities of the surface ; that in one locality which 

 he had repeatedly examined it conforms with the uneven por- 

 tions of a mass of syenite, with which it is so associated as to 

 reveal its more recent origin ; and that, therefore, it is not of 

 nummulitic derivation, but was deposited in a vein-like form, 

 the materials having been probably forced up into the cavi- 

 ties from below w T hile in a vaporous state. 12 A, May 11, 28. 



PELOBIUS, A NEW EEESH-WATER KHIZOPOD. 



Of the discoveries in natural history Avithin the past few 

 years, scarcely any are considered of greater importance than 

 that of Professor Huxley, of the occurrence, in the depth of 

 the ocean, of a living, organized mass of an animal nature, 

 termed Bathybius, its relationships to other forms of animal 

 life, both recent and fossil, having proved to be of the highest 

 interest. This has recently been supplemented by the dis- 

 covery, on the part of Dr. Greeff, of a somewhat similar sub-, 

 stance existing in fresh w T ater, which he characterizes as a 

 shell-less fresh- w T ater rhizopod, remarkable for its gigantic 

 stature in comparison with all previous-known organisms of 

 the kind. This substance, which he calls Pelobius (a name 

 which Nature, from which we borrow this account, states to 

 have long been preoccupied), occurs in many standing waters 

 with a muddy bottom, especially such as have continued in 

 that state for a long time without having dried up. This 

 substance never disappears from these waters, but remains 

 throughout the year, great masses appearing sometimes in 

 one place and sometimes in another, in their external form 

 presenting the appearance of more or less spherical lumps, 

 varying from one or two millimetres in diameter down to the 

 most minute points, scarcely perceptible by the naked eye. 

 These are said to be so densely filled with mud particles, di- 

 atomacere, etc., that by transmitted light they can scarcely 

 be distinguished from the actual mud without experience and 

 careful examination ; they may, consequently, be compared 



