688 DE. W. B. CAEPES'TER ON THE STRUCTURE, PHYSIOLOGY, AND 



action by which the ingestion of food is really accomplished. An examination of the 

 residual matters ejected through the anal orifice enabled him to determine that these 

 were spicules of Sponges, Bacillarite, and remains of other microscopic organisms. 



In the same year also there appeared the " Prodrome d'une Monographie des Radi- 

 aii*es ou Echinodermes" of Professor Agassiz ; which left the position of Comatnla among 

 the Crino'idca, and of the Crino'idea as a family of the Stellerida, very much the same 

 as in Blai^ville's arrangement. 



"We next come to the memoir of Professor JoH. Muller, " Tiber den Bau des Penta- 

 crinus Caput-Medusce" communicated to the Berlin Academy' on the 30th April, 1840, 

 and the 13th May, 1841; which constitutes the most important contribution that has 

 been made up to this time, not only to the anatomy of the Crinoidea generally, but to 

 that of Antedon in particular ; the structure of that type having been carefully investi- 

 gated by Professor MUller, with the view of throwing light on that of the parts of his 

 specimen of Pentacnnus which were unfortunately deficient, as well as for the sake of 

 determining the precise relations of these two genera. I shall have such constant occa- 

 sion in the subsequent portions of the present communication to refer to the labours of 

 my distinguished predecessor, that I shall here only express my high appreciation of 

 their value, and my regret that he did not himself live to supply that completion and 

 extension of them, for which he is understood to have collected materials during a -vdsit 

 he made to the coast of Norway, shortly before his death, for the purpose of studying 

 Antedon in its living state. His investigation of the skeletons of Pentacnnus and of 

 Antedon, and of the relations of their different jiarts as indicated by their muscular 

 connexions, was conducted in a thoroughly philosophical spmt ; and afforded the basis 

 for a more satisfactory determination of the homologous parts in the fossil Crinoidea 

 than had been possible on the comparatively empii'ical method of J. S. Miller. The 

 nomenclature which he introduced has completely superseded that of his predecessor ; 

 and, with some modifications, it will probably remain as the standard by which all 

 descriptions of Crinoidea will be ch-awn. In subsequent communications to the Berlin 

 Academy, which are all embodied in his Memoir " Uber die Gattung Comatula und 

 ihre Arten"^, he laid down the principles on which he considered that the systematic 

 arrangement of the numerous species now known might best be founded ; and he gave 

 descriptions of these species, based on the characters thus indicated, and for the most part 

 drawn from personal examination of the specimens contained in the principal European 

 museums. 



It was by Professor Edward Forbes that the title of the Crinoidea to rank as a 

 distinct Order of Echinodermata seems to have been first perceived ; and in his ' History 

 of British Star-fishes, and other Animals of the Class Echinodermata,' published in 1841, 

 he constituted such an Order under the title of Pinnigrada, which he conferred upon it 

 in conformity with his fundamental idea of classifying Echinodermata, like Arachnoder- 



' AbhancUungcn der Kiinigl. Akadcmio dcr Wissenscliafteii zu Berlin, 18-H. 

 - Abhandluugeu der Konigl. Akademie der "Wissenschaften zu Berlin, 1847. 



