276 



NATURE 



[August 25, 1923 



making disease, some 40 per cent, of existing poverty 

 having been estimated to be due to it. In a full 

 discussion of housing difficulties, Dr. Niven points out 

 the impossibility of securing satisfactory' housing in 

 central districts on economic lines, and in this connexion 

 suggests that the necessary expenditure might be 

 diverted from what is wasted on alcoholic drinks. He 

 asks, " Can there be any doubt that the liquor trade 

 paralyses the hands of the social reformer and keeps 

 the people poor ? " 



Only a few of the important subjects discussed in 

 this valuable review of public health progress have 

 been mentioned ; but we trust that the attention now 

 directed to it may lead to its study by many who at 

 present realise inadequately the vast strides already 

 made in the prevention of disease and in the improve- 

 ment of the public health. 



The Ichthyosaurians. 



Die Ichthyosaurier des Lias und ihre Zusammenhdnge. 

 Von Friedrich von Huene. Pp. viii + 114 + 22 

 Tafeln. (Berlin : Gebruder Bomtraeger, 1922.) 255. 



BARON F. VON HUENE is well known by his 

 numerous writings on fossil reptiles of strange 

 and rare types which are represented by more or less 

 fragmentary specimens. He has now turned his 

 attention to the comparatively familiar ichthyosaurians, 

 of which, perhaps, more nearly complete skeletons 

 occur in museums than of any other reptiles. As he 

 remarks, the osteology of this group is now rather 

 well known. He therefore devotes his work chiefly 

 to a definition of the species, with an attempt to arrange 

 them in genera and to determine their relationships. 

 He has made many new observations on the specimens 

 from the Lias of south Germany, of which he pub- 

 lishes important illustrations. In this research he 

 acknowledges especially the valuable help of Dr. 

 Bemhard Hauff, of Holzmaden, whose fine prepara- 

 tions of Liassic reptiles and fishes are now scattered 

 through many museums. 



Baron von Huene adopts the usual classification of 

 the ichthyosaurians into those with the fore paddles 

 broad and those with the paddles long and narrow. 

 He also considers that these two groups remain distinct 

 from the beginning to the end of the career of these 

 marine reptiles. He recognises and names more 

 genera, however, than have hitherto been supposed 

 to occur, and his taxonomy is not likely to meet 

 with general approval. Ichthyosaurus, for example, 

 altogether disappears as a generic name ; and other 

 generic names already exist having priority over some 

 of the new names proposed. The taxonomy is indeed 

 the least acceptable part of the work. 



NO. 2808, VOL. I I 2] 



The stratigraphical distribution of the ichthyo- 

 saurians in the Lias of south Germany is shown in a 

 table, and it would be interesting to make an equally 

 detailed study of the distribution of the species in the 

 several zones of the Lias in England. Except the 

 typical species of Ophthalmosaurus from the Oxford 

 Clay, the later ichthyosaurians are still known only 

 by comparatively fragmentary specimens. 



The author concludes his work with a large table 

 of outline sketches to illustrate the evolution of the 

 ichthyosaurians from their first appearance in the 

 Middle Trias to their disappearance in the Upper 

 Cretaceous. At the beginning he places the small 

 Mesosaurus, of Permian age, which he considers may 

 be related to the semi-aquatic primitive ancestor of 

 the whole group, which still remains unknown. The 

 Triassic forms are represented as long-bodied, with 

 the backbone only shghtly bent downwards where a 

 small caudal fin arises. The caudal fin is completed 

 before the end of the Liassic period ; and it becomes 

 more effective as a propeller by the shortening of the 

 caudal pedicle in the Upper Jurassic forms. The only 

 Cretaceous species sufficiently well known for restora- 

 tion is represented as again slender, with a compara- 

 tively small though complete caudal fin. 



The volume is excellently printed and illustrated, 

 and we commend it to the notice of all students of 

 vertebrate palaeontology, A. S. W. 



Our Bookshelf. 



Die steinzeitlichen Stationen des Bir stales Z7cischen Basel 

 und Delsberg. Von Fritz Sarasin. Prahistorischer 

 und anthropologischer Teil von Fritz Sarasin. 

 Palaontologischer Teil von H. G. Stehlin, unter 

 Mitwirkung von Th. Studer (Aves). Mit 32 Tafeln 

 und 20 Textfiguren. Neue Denkschriften der 

 Schweizerischen Naturforschenden Gesellschaft. 

 Band liv. Abh. 2. (Basle, Geneva und Lyons : 

 Georg und Co., 1918.) n.p. 



The above volume, only recently issued though dated 

 1918, contains some 290 pages of text, with 32 full-page 

 illustrations at the end. There are also some 20 

 figures in the text giving sections, maps, and the like. 

 A full and careful account of a number of diggings just 

 south of Basle is given, including a description not only 

 of the archaeological finds, but also of the mammalian 

 and bird remains. The whole forms a useful addition 

 to our knowledge of prehistoric times in this region. 



The first part of the volume is devoted to a description 

 of finds from a number of caves. The industries 

 recognised are Neolithic, Azilian, and Magdalenian. 

 Owing to the area being outside the region of glaciation, 

 the determination is done on purely typological grounds. 

 A Neolithic burial (with skeleton complete) was un- 

 earthed, and a full account is given. In one instance 

 " painted pebbles " were discovered in an Azilian layer. 

 It is interesting to find these typical Azilian objects so 

 far north. There is evidence of Azilian culture as far 



