224' Bibliographical Notice. 



We now come to the three southern forms with jet-black 

 hoods, viz. : — 



6. Falco melanogenys. (The Australian Peregrine Falcon.) 

 A very distinct species, distinguished bj its black face and 



close-set narrow barring. 



Hab. Australia northwards to Java (judging by Schlegel's 



figure in the ' Vogel van Nederlandsch Indie '). 



7. Falco minor. (The South -African Peregrine Falcon.) 

 The smallest of all Peregrines. 

 Hab. South Africa and Madagascar. 



8. Falco Cassini. (The Chilian Peregrine Falcon.) 

 Allied to F. melanogenys of Australia, but differing as 



above mentioned. The young deeper rufous than in any of 



the other Falcons. 



Hab. Straits of Magellan and Chili. 



BIBLIOGEAPHICAL XOTICE. 



Dr. Ehrenherg^s Microgeological Studies. [" 3Iikrogeologische Studien, 

 &c.," Monatsbericht kon. preuss. Akad. Wissensch. Berlin fiir April 

 1872, pp. 265-322 : 1872.] 



This is the abstract of a memoir which the veteran, and now nearly 

 octogenarian, naturaUst of BerHn has laid before the Academy as the 

 results of his long-continued methodical researches on the microscopic 

 life of the sea-bottom of all zones, especially in its relationship 

 to past life and its influence on geological studies. From 1836 to 

 1871 Ehrenberg has given to the world numerous descriptions and 

 hundreds of good figures (all magnified 300 diameters) of microscopic 

 objects, recent and fossil, the latter mainly in his ' Mikrogeologie ' 

 (1854). However numerous the shore-sands, dredgings, and deep- 

 sea soundings he has examined, yet, says he, the spots are so widely 

 scattered over the map as to show how much more we have to learn 

 of the sea-bed. 



The distribution of warm and cold currents is now beginning to 

 be understood, he remarks ; and the dispersion and relative abimd- 

 ance of deep-sea life, and the formation of sihceous and calcareous 

 ooze and muds, are stUl to be more deeply studied. At all events, the 

 sounding-Une has never gone so deep but the microscope shows that 

 nature is rich there also with life. We know not, he says, what 

 forms of being, minute or gigantic, exist throughout the abyssal 

 depths ; and " the abundant occurrence of PeruUnia in the flint of 

 the deep-sea chalk, as well as the living luminous animals on 

 the ocean's surface, and even at the deep bottom off Florida, point 

 to a possibly periodic, and even permanent, strong light in those 



