abstracts: zoology 503 



GEOLOGY — The structure of parts of the central Great Plains. N. H. 



Darton. U. S. Geol. Survey Bull. 691-A. Pp. 26, with maps, 



sections, and illustrations. 1918. 

 This report shows the structural features, such as domes and anticlines, 

 that occur at many places in Kansas, Nebraska, South Dakota, Colo- 

 rado, and Wyoming. While there is no evidence that the strata con- 

 tain oil or gas in commercial pools these folds are more favorable for the 

 location of tests than the basins or the monoclines. Only the drill can 

 determine whether or not oil is present. It is believed that a presenta- 

 tion of all available facts as to structural conditions in this region is 

 warranted by the prevailing great interest in the possibility of the 

 occurrence of petroleum and gas. 



R. W. Stone. 



ZOOLOGY. — The unstalked crinoids of the Siboga expedition. (Mono- 

 graph XLII6 of: Uitkomsten op zoologisch, botanisch, oceano- 

 graphisch en geologisch gebied verzameld in Nederlandsch Oost- 

 Indie 1899-1900 aan boord H. M. Siboga onder commando van 

 Luitenant ter zee P kl. G. F. Tydeman.) Austin H. Clark, U. 

 S. National Museum. Leiden, March, 1918. Pages i-ix, 1-300. 

 17 text figures; plates I-XXVIII (except IV and X, the origi- 

 nals of which were lost on the ''Laconia"), of which plates I-X 

 are in colors. 

 This memoir, which is an extension of and a supplement to the 

 Crinoids of the Indian Ocean published by the same author (Calcutta, 

 1912), gives a monographic account of the comatulid fauna of the 

 East Indies. Keys to all the species, genera, and families are included. 

 The identity of the urinoid fauna of the Arc Islands with that of 

 Australia is mentioned, and the close similarity between the Sumbawa- 

 Moluccas fauna and that of southern Japan is emphasized. 



There are known at present 576 species of recent crinoids, distrib- 

 ured in 142 genera; in the course of her explorations the "Siboga" 

 collected 163 species, representing 71 genera; of these 73 species and 3 

 genera were new to science, 



A. H. C. 



