LATTICE WORKERS, OR POLYCYSTINA. 69 



united influences they are far more important than 

 all these animals." 



Yet this was not the first time that these minute 

 animals, or rather their skeletons, became known, for 

 already previous to 1838, a few fossil forms had been 

 observed, and in that year these were grouped 

 together by Ehrenberg under the name of Polycystina, 

 which they still partly retain. Prior to the discovery of 

 the Barbados earth these organisms had been found 

 in the chalks and marls of Sicily, Oran, and in Greece, 

 and sparingly in the Tripoli of Richmond in Virginia, 

 and in Bermuda. 1 Later on they have been brought 

 up in profusion, in a living condition, from out of the 

 depths of the sea. Our whole knowledge of them 

 may be circumscribed within the limits of the last 

 half century. 



It would be an interminable task to enumerate and 

 describe all the varied forms of these skeletons or shells, 

 (Plate II.), but Mrs. Bury has given a characteristic 

 introduction to their external appearance : " Among 

 the most striking differences of form," she says, " may 

 be mentioned that some are like numerous little 

 globes growing out of each other, beginning with a 

 small one at the apex, and each increasing in size as 



1 A resume of what was known of them, in their relation to 

 existing animals, is contained in " Microscopical Siliceous 

 Polycystina of Barbados," by Sir R. Schomburgh, in " Annals 

 of Natural History," vol. xx. p. 115. 1847. 



