Sbptembeb 10, 1915] 



SCIENCE 



345 



cent crinoids generally has ever been given be- 

 fore. 



There is not space to review the questions 

 of zoological relationships discussed — some of 

 ■which are speculative, and will doubtless meet 

 with criticism — nor the many new discoveries 

 touching the structure and characters of the 

 crinoid organism, which testify to the indus- 

 try of the author. Among the more general 

 conclusions to which these researches have 

 led, the following may be mentioned: 



1. The Crinoids of the recent seas are far 

 more numerous, both in individuals and in 

 species, than is commonly supposed, and their 

 relative importance does not fall short of that 

 of the other echinoderm groups. 



2. The Crinoids, after a paleontological 

 record almost without a parallel for duration 

 and for variety in development, are repre- 

 sented in the recent seas chiefly by two highly 

 aberrant types, viz: (1) the Pentaerinites, 

 which have departed widely from their proto- 

 types by enormously increasing the length of 

 the column through the indefinite reduplication 

 of the first stem joint, or proximale; and (2) 

 the Comatulids, which have departed just as 

 widely by discarding the column and com- 

 pressing what is virtually the entire column 

 of the pentaerinites within the compass of a 

 single highly cirriferous proximale. Thus 

 while the two groups are parallel to each other, 

 and are descended from the same ancestral 

 stock, and represent the same phylogenetic 

 stage, during their development they have di- 

 verged from, their phylogenetic mean in ex- 

 actly opposite directions; and both groups are 

 therefore far removed from the direct line 

 representing the progressive development of 

 the class. 



3. These two aberrant types dominate the 

 recent seas to such a degree that in compari- 

 son with them all the other types become rela- 

 tively insignificant. The comatulids, although 

 in their relation to the fossil crinoids merely 

 an inconspicuous family, far outnumber all of 

 the other existing crinoids taken together, at 

 the same time extending through a much 

 wider geographical, bathymetrical and thermal 

 range. They exist in a vast array of diverse 



forms, none of which depart in any great de- 

 gree from the general structure of the group, 

 so that their classification necessitates the 

 creation of numerous subfamilies, and fam- 

 ilies, and higher groups, which are not syste- 

 matically comparable to similar groups in the 

 stalked crinoids. 



4. Among the Eecent Crinoids the calyx, 

 usually reduced to insignificant proportions, is 

 of comparatively little systematic value — the 

 classification being placed chiefly upon the 

 column (or homologous structures), and the 

 proximal pinnules. This is, broadly speaking, 

 the reverse of the conditions in the fossil 

 forms, and this fact involves the recognition 

 of characters for the diiferentiation of species 

 and genera wholly diflierent from those em- 

 ployed in dealing with the fossils. The appli- 

 cation of these criteria to the study of the col- 

 lections and material above mentioned has re- 

 sulted in the proposal of nearly 100 new gen- 

 era, and the description of several hundred 

 species new to science, among the comatulids 

 alone, the systematic treatment and illustra- 

 tion of which are to follow in a succeeding vol- 

 ume. 



5. The author believes the echinoderms to 

 be a highly abberrant offshoot from a primitive 

 crustacean stock, and that they are far from 

 being the anomalous creatures they are com- 

 monly considered. 



The thanks of all students of the echino- 

 derms are due to the authorities of the Na- 

 tional Museum for their liberality in facilita- 

 ting the publication of the results of these re- 

 searches in so thorough and comprehensive a 

 manner, and in thus giving to the scientific 

 public a work which is destined to take rank 

 with the great monographs following the 

 Challenger Expedition — a series which in its 

 entirety stands as one of the finest contribu- 

 tions to the knowledge of marine zoology ever 

 produced. Frank Springer 



THE FBOCEEDINGS OF THE NATIONAL 

 ACADEMY OF SCIENCES 



The eighth number of Volume 1 of the 

 Proceedings of the National Academy of Sci- 

 ences contained the following articles : 



