m 



:256 



THE CANADIAN NATURALIST. 



[Vol. Vii. 



i)erp long ago recognized them as forming an important consti- 

 ♦r.eot of the English chalk, and supposing tiiem to result from 

 a rearrangement and partial crystallization of the particles of car- 

 bonate of lime, called them '• niorpholites." The name by which 

 they are now known was applied to them by Prof Huxley, who 

 found them to be characteristic of many deep sea sediments, 

 where t'.icy appear in corjunction with the Aiuoeba-like Bathi/- 

 liiis. It is still fl question 'n dispite, whether they form an 

 integral part of that orgiuism. RhabdoUths were discovered by 

 Dr. 0. Schmidt in 1872* in the Adriatic Sep, in association with 

 Coccoliths, with wlr.ch they appear to be closely allied in struc- 

 ture and mode of increase. I do not know that they have 

 lieretofore been found in the fossil state. 



X /250 



Fig 2. Various forms of Coccoliths (a) and Rhabdoliths (i) from 

 the Cretaceous of Manitoba. 



In the samples of Cretaceous limestone from Manitoba and 

 Nebraska, both Coccoliths and Rhabdoliths are abundant, and 

 ■constitute indeed a considerable proportion of the substance of 

 the rock. The engraving represents a sel .ction of the forms 

 observed, magniaed about 1250 diameter' The Rhabdoliths 

 i\gree closely with those figured by Dr. ^Schmidt, f and pass 



• Ann. and Mag. N. H. 1872. 



t Loc. Cit. PI. xvii. 



