September 10, 1915] 



SCIENCE 



343 



upon the Challenger collections, these volumes 

 constituted a thorough monograph of the 

 group as it was known at those dates. During 

 the ensuing quarter of a century extraordinary 

 activity in marine exploration has prevailed in 

 all the oceans, resulting in an enormous in- 

 crease of material for study — both in the way 

 of specimens, and of accurate records of oc- 

 currence and distribution, by which the influ- 

 ence of depth, temperature and ocean currents 

 upon the growth and modification of crinoid 

 faunas can be studied in a manner not 

 hitherto possible. New species and genera 

 have thus been brought to light to an extent 

 wholly unexpected. With this great multipli- 

 cation of new forms, it has become increas- 

 ingly evident to those interested in the sub- 

 ject that the criteria employed for discrimi- 

 nation of the Fossil Crinoids are only appli- 

 cable in a limited degree to the Recent, and that 

 some new method of treating the latter is re- 

 quired in order to adequately deal with the 

 new facts. The practical working out of such 

 a method is perhaps the most important gen- 

 eral result of Mr. Clark's researches; this will 

 be fully developed in his monograph, of which 

 the present volume is the introductory part, to 

 be followed by others treating systematically 

 the genera and species of the Comatulids and 

 Stalked Crinoids. 



Much of the work to be embodied in the 

 subsequent volumes has already been done, and 

 the results published in preliminary form in a 

 series of papers appearing in various American 

 and foreign journals during the past eight 

 years, which give evidence of the extraordinary 

 energy with which the author has prosecuted 

 his studies. These publications, beginning 

 with the description of the new genus Ptilo- 

 crinus in June, 190Y, now amount to a total 

 of 114 papers, of which 23 were issued in jour- 

 nals of England, Denmark, France, Holland, 

 Germany, Monaco, India, New South Wales 

 and western Australia. Some of these are 

 really treatises in permanent form — notably 

 that upon the " Crinoids of the Indian 

 Ocean," a fine quarto volume of 325 pages and 

 59 figures, published in 1912 by the trustees 

 of the Indian Museum at Calcutta; this was 



based upon the collections made during a num- 

 ber of years by the Royal Indian Marine Sur- 

 vey steamer Investigator, and placed by the 

 authorities of the museum in Mr. Clark's 

 hands for description. Another quarto work 

 of 209 pages and 10 plates is " Die Crinoiden 

 der Antarktis," published in Germany upon 

 the collections made by the steamer Gauss, of • 

 the Deutsche Sudpolar-Expedition, which were 

 sent to the author for investigation. A paper 

 upon a collection of crinoids from the Zoolog- 

 ical Museum of Copenhagen was published in 

 the "Vidensk Medd. fra den Naturhist. i 

 Kjobenhaven," 1909; one of 100 pages on the 

 "Recent Crinoids of Australia," in the Me- 

 moirs of the Australian Museum at Sydney, 

 in 1911; and another in the same year on the 

 " Crinoidea " of the Hamburg Southwest Aus- 

 tralian Expedition was published as Band III., 

 Lieferung 13, of the scientific results of that 

 expedition. 



Of the remaining 91 papers published in 

 America, the greater part have appeared in 

 the Proceedings of the U. S. National Mu- 

 seum. Out of the total number of papers, 69 

 have been upon collections examined. Some 

 idea of the wide range of the researches upon 

 which this monograph is founded may be had 

 from an enumeration of the collections, and 

 of material from expeditions which have been 

 studied. In addition to the already large col- 

 lections of the United States Bureau of Fish- 

 eries, and of the National Museum, accumu- 

 lated by the dredgings of various Coast Sur- 

 vey and Fisheries vessels, including the recent 

 cruises of the Albatross in the Pacific Ocean, 

 the following foreign museum and special col- 

 lections have been placed at Mr. Clark's dis- 

 posal and sent by their owners to Washington 

 for his use: Zoological Museum, Copenhagen; 

 Hamburg Museum, containing the types of 

 Hartlaub's species; Museum fiir Naturkunde, 

 Berlin, containing the type material of 

 Johannes MiiUer's classical works upon the 

 recent crinoids; Indian Museum, Calcutta; 

 Australian Museum, Sydney; Western Aus- 

 tralian Museum and Art Gallery, Perth; Sv. 

 Gad collection from Singapore; Svensson col- 

 lection from East Asia, Copenhagen. Also the 



