1318 THE STORY OF THE UNIVERSE 



nutrition is effected in a very gentle manner. The 

 grooves of the pinnules and arms are richly ciliated. 

 The crinoid expands its arms like the petals of a full- 

 blown flower, and a current of sea-water bearing 

 organic matter in solution and suspension is carried 

 by the cilia along the brachial and radial grooves 

 to the mouth. In the stomach and intestine the 

 water is exhausted of assimilable matter, and the 

 length and direction of the excretory proboscis pre- 

 vent the exhausted water from returning at once into 

 the ciliated passages. 



Two other fixed crinoids were dredged from the 

 Porcupine, and these must be referred to the Apio- 

 crinidae, which differ from all other sections of the 

 order in the structure of the upper part of the stem. 



The Apiocrinidae attained their maximum during 

 the Jurassic period, when they were represented by 

 many fine species of the genera Apiocrinus and 

 Millericrinus. The chalk genus Bourguetticrinus 

 shows many symptoms of degeneracy. Rhizocrinus 

 loffotensis, M. Sars, was discovered in the year 

 1864, at a depth of about 300 fathoms, off the 

 Lofoten Islands, by G. O. Sars, a son of the cele- 

 brated Professor of Natural History in the Uni- 

 versity of Christiania, by whom it was described in 

 the year 1868. It is obviously a form of the Apio- 

 crinidae still more degraded than Bourguetticrinus, 

 which it closely resembles. 



The genus Bathycrinus must also be referred to the 

 Apiocrinidae, since the lower portion of the head con- 

 sists of a gradually expanding funnel-shaped piece, 

 which seems to be composed of coalesced upper stem- 



