432 • NOTES. 



Philippines live in 0° F. ; in the Mediterranean, in 20-30° F. ; in the 

 North Atlantic, in 30-60° F. 



The largest number of Sendrochirotee in the Philippines live in 1- 

 10° F. ; in the Mediterranean, in 10° F. ; in the North Atlantic, in 

 20-60° F. 



The largest number of Sijnaptidai in the Philippines live in 0° F. ; in 

 the Mediterranean, in 1-10° F. ; in the North Atlantic, in 1-10° F. 



Brachiopoda — Liiigula — which occur only at great depths in the 

 North Sea, in tropical seas are found near the surface, and even some- 

 times exposed to the ebb and flow of the tide. 



Note 54, prye 137. If we assume that the place where we find the 

 greatest number of individual species and genera living together is to be 

 regarded as their primary habitat — or centre of distribution — then the 

 Crinoids, Sponges, and many other remarkable forms now living at the 

 bottom of the sea must decidedly be designated as cold-water animals. 

 For by far the larger number of them live at depths where the tempera- 

 ture remains without any conspicuous variation throughout the year at 

 the low point of from 1-2' C. 



Note 55, page VA'i. Schmankewitsch's observations on Artemia and 

 Branchipus promise to be of the highest interest in this respect. He 

 found that in individuals which had tlieir assimilation interfered with 

 by a too considerable increase or diminution of the saline components 

 of tlie water, the injurious efEects of this saltness could be entirely neu- 

 tralised by a diminution or, on the ol her hand, by an increase of tempera- 

 ture. He furthermore observed that the size of the gill-sacs of Artemia 

 was directly dependent on the temperature of the water, increasing in 

 size with a higher degree of warmth. However, he detracted from the 

 value of his observations by introducing 'nto his estimates one wholly 

 unknown quantity, namely, the amount of air contained in the water 

 (in his experiments), and by attempting to explain everything by the 

 variable proportion of air contained in water of different salinity at 

 different temperatures. General propositions, such as he puts forward 

 hypothetically as to the part played by the air contained in the water, 

 are in such a case of no irse, or even misleading. 



CHAPTER V. 



Nate 56, page 146. It was impossible to enumerate in the text all 

 the fresh-water animals that live in salt water ; I here subjoin a tolerably 

 complete list, which, however, makes no pretention to being absolutely 



exhaustive. 



