Deoembeb 25, 1908] 



SCIENCE^ 



923 



fessor Charles E. Vanderkleed, as professor of 

 pharmaceutic chemistry. 



DISCUSSION AND CORRESPONDENCE 



AFTONIAN SANDS AND GRAVEL IN WESTERN IOWA 



To THE Editor of Science : During the past 

 summer investigations made by the writer for 

 the Iowa Geological Survey revealed wide- 

 spread deposits of Aftonian sands and gravels 

 in the western part of Iowa. 



The beds, where undisturbed, in some cases 

 reach a thickness of 35 feet, and furnish fine 

 examples of cross-bedding and interbedding of 

 sands and gravels. They lie unconformably 

 between the Pre-Kansan and Kansan drifts, 

 and were evidently deposited in flooded streams 

 during an interglacial period. 



That the climate of this period was com- 

 paratively mild is shown by the presence of 

 fossil shells of species of moUusks still living 

 in Iowa, belonging to the genera Unio, 

 SphcBrium, Pisidium, Yalvata, Planorhis, 

 Ancylus, etc., and of numerous bones and 

 teeth of extinct herbivorous mammals belong- 

 ing to the genera Elephas, Mamut, Eqmis, etc. 

 The latter were found exclusively in the coarse 

 gravels, while the former occurred chiefly in 

 the finer sands. 



At a number of points these sands and 

 gravels were plowed and folded, and heaped 

 up to a height of more than 100 feet above the 

 Missouri Valley by the mass of Kansan ice 

 which passed over them and in some cases 

 even displaced the underlying Pre-Kansan. 



The discovery is of special interest because 

 these western gravels may now be definitely 

 referred to the Aftonian, and because the 

 fossils present a fauna practically new to that 

 horizon, and throw light upon the climatic 

 conditions which existed during the period of 

 deposition. B. Shimek 



State Univeesitt of Iowa, 

 December 14, 1908 



SCIENTIFIC BOOKS 



National Antarctic Expedition. Vol. IV., 



Zoology. London, British Museum, 1908. 



4°, pp. -6, 279, and 65 plates. (Containing) 



Solenogastres, by H. E. Nierstrasz ; Aptera, 



by G. H. Carpenter; Schizopoda, by W. M. 



Tattersall; Copepoda, by R. Noeris Wol- 



fenden ; Echinoderma, by E. Jeffrey Bell ; 



Echinoderm larvse, by E. W. MacBride and 



J. C. Simpson; Myzostomidce, by E. Eitter 



VON Stummer-Erauenfels; SipunculidoB, by 



W. E. Lanchester; Actinias, by J. A. 



Clubb; Tetraxonida, by E. Kirkpatrick; 



and Calcarea, by C. F. Jenkin. 



Under the supervision of Mr. E. Jeffrey 

 Bell, of the British Museum, another fine 

 volume has been added to the series describ- 

 ing the scientific results of the expedition to 

 the Antarctic under Captain Scott, E.N., and 

 his companions. A brief reference to the sub- 

 ject-matter of the various memoirs is all that 

 our space permits. 



A single species of Proneomenia was ob- 

 tained in about latitude of Y8° S. This is de- 

 scribed by Nierstrasz in great detail, followed 

 by a proposed division of the family Proneo- 

 meniidJE into a large number of groups, based 

 on the structure of the glands and radula. It 

 may be heterogeneous, and the forms of which 

 it is composed may be related to different 

 members of the Proneomeniidfe. 



Carpenter reports the presence of a wingless 

 insect belonging to the Collembola in moss 

 from Granite Harbor in 77° S. latitude, 

 though the specimens were in rather im- 

 perfect condition. Enough was made out to 

 allow placing it in a new genus, Gomphio- 

 cephalus, of the Poduridffi. 



The Schizopod Crustacea collected embraced 

 considerably over ten thousand specimens, 

 but of these the vast majority belong to a 

 single species and the total number of species 

 collected is only thirteen. The abundant ma- 

 terial of the Discovery party enables Mr. 

 Tattersall to combine under Dana's original 

 name four subsequently described species 

 taken from mutations due to age, or vari- 

 ability. Two species are cited as " bipolar " 

 but further investigations of the deep sea may 

 reveal them as cosmopolitan. 



Of the Copepods seven proved new, and one 

 new genus, Paralaiidocera, is proposed by 

 Wolfenden. Of the twenty-eight Antarctic 

 species recognized, two are regarded as 

 " bipolar," though many have Arctic an- 



