22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 'J2 



So far as we can see it is with the recent species which are found 

 within these temperature Hmits that the fossil crinoids best agree, 

 and one might hazard the guess that it was principally, if not entirely, 

 within these temperatures that the crinoids of the post-palaeozoic 

 faunas, characterized by a very great development of the Articulata, 

 were developed. 



FOOD 



Duchassaing records that the stomach contents of a specimen of 

 Isocrinus dccorns which he fished up in relatively very shallow water 

 at Guadeloupe consisted only of the remains of small crustaceans. 



Bronn, summarizing previous accounts, wrote that the stomach 

 contents of Isocrinus were made up of the remains of small crus- 

 taceans, while those of the comatulids consisted of diatoms such as 

 Navicula, Bacillaria, Actinocyclus and Coscinodiscus, of Tethya, and 

 of many types of entomostraca. 



W. B. Carpenter said in 1866 that in the very numerous specimens 

 of Antedon bifida from Arran of which he examined the contents of 

 the digestive cavity he never found anything other than microscopic 

 organisms, and the abundance of the horny rays of Peridinium tripos 

 made it evident that in this locality that organism is one of the 

 principal articles of food. But in specimens from other localities he 

 found a more miscellaneous assemblage of alimentary particles, the 

 most commonly recognizable forms being the horny casings of ento- 

 mostraca or of the larvse of higher crustaceans. 



In his account of Hyponome sarsii (the visceral mass of Zygometra 

 microdiscus) Loven states that in the ambulacral grooves he found 

 masses consisting of minute crustaceans, larval bivalves, and other 

 remains of food. 



In 1876 W. B. Carpenter wrote that the contents of the alimentary 

 canal of Antedon bifida both in the pentacrinoid stage and in the adult 

 consists of minute entomostraca, diatoms, spores of algae, etc., but 

 in his Lamlash specimens especially of Peridinium tripos, which was 

 usually very abundant in that locality. He also notes that the contents 

 of the alimentary canals of the various types of pentacrinites ex- 

 amined by him are of the same nature. 



P. H. Carpenter says that the food of a crinoid is considerably 

 varied in its nature according to the character of the sea bottom on 

 which it lives. The horny casings of entomostraca and the larvae of 

 larger Crustacea are frequently to be found in the digestive tube 

 together with the frustules of diatoms, spores of algae, etc. In sec- 

 tions of Bathycrinus, Rhisocrinus, Isocrinus and Endoxocrinus from 

 deep water the silicious skeletons of radiolarians may be found in 



