44 SCIENCE PROGRESS. 



southern oceans, the Rhabdospheres and Coccospheres, 

 which we must regard as pelagic Algae, are playing the 

 same role in the tropical and temperate seas. The broken- 

 down parts of these organisms known as Rhabdoliths and 

 Coccoliths are found in the globigerina oozes, and they have 

 practically the same geological history as the diatoms. The 

 problem presented by these remarkable organisms is un- 

 doubtedly of palseontological interest, but it is primarily a 

 biological one since so little is known of the minute structure 

 and mode of life of the contemporary forms. 



Though Lithothamnion appears first in the Senonian 

 (Cretaceous) beds it may eventually prove to be as old as 

 the Muschelkalk (Trias). It is not, however, until we reach 

 the Tertiary rocks that this coralline is found occurring 

 massively, as it does in the Lower Eocene. The Leitha 

 limestone (Miocene) and Pisolite limestone and the Num- 

 mulitic rocks owe their origin in great part to this con- 

 temporary genus. Every botanist who has waded over a 

 coral reef must have been struck by the massive occur- 

 rence of this rock-building Alga, the activity of which 

 has been somewhat neglected by students of coral reefs. 

 I think it was Mr. Darwin who remarked that it often 

 formed the cement that bound the coral together. It 

 frequently does more than this. A large number of the 

 specimens brought back by Mr. Bassett Smith, R.N., from 

 his survey of the Macclesfield Bank were Lithothamnia, 

 and to witness what this Alga can do in forming a beach 

 in the absence of coral one need not go beyond the 

 British Islands. It is the only Floridean fossil of certain 

 determination unless Mr. Seward's Algites should prove to 

 be of this group. 



The fossil DasycladacecE which we owe to the researches 

 of Munier-Chalmas (11 and 12) are of an importance far 

 exceeding all other results in fossil Phycology. With a 

 power of extraordinary divination this author has rescued 

 from amoni>" the fossil Foraminifera and elsewhere a series 

 of Tertiary and other Algae, and having accomplished this 

 remarkable scientific feat has maintained an almost equally 

 remarkable reticence on the subject. In fact we owe to 



