238 LG JOWIRINALL (UF CIS OILOG 37, 
The femur is 455 mm. long, and in nearly every respect like that 
of man; slight differences are only seen in the absence of an Angulus 
medialis, in the slight development of the Planum popliteum and the 
Linea obliqua, and in the concave form of the Crista intertrochanterica. 
The corresponding size of man, with a femur of 455 mm. is given as 
170 cm. 
The important question, of course, is asked: Is the material at the 
disposition of Dr. Dubois sufficient to sustain the conclusions so con- 
fidently expressed. We know that the capacity of the normal human 
cranium varies from 1000-1800 cubic centimeters; /Pithecanthropus, 
with a capacity of over 1ooo, is not necessarily excluded from this 
series. In regard to the femur it is questionable whether the distinctive 
characters given by Dr. Dubois hold good, if a great number of human 
femora is examined; besides, the femur shows an extensive exostosis 
in the upper half. The evidence brought forward by Dr. Dubois certainly 
does not seem sufficient for the establishment of a new genus and 
family, forming the missing link between the Simiidz and Hominide. 
The publication of the fauna contemporary with /ithecanthropus is 
looked for with much interest. 
G. Baur. 
The Fins of Ichthyosaurus. 
As far back as 1838 Owen* had noticed the fact that nearly all the 
specimens of Ichthyosaurus from the English Lias showed a disloca- 
tion in the tail-vertebrze. This distocation or bend was found at the 
posterior one-third of the tail, generally about the thirtieth caudal 
vertebra in the /chthyosaurus communis; the terminal portion con- 
tinued, after the bend, almost as straight as the portion of the tail 
preceding it. From this Owen reached the conclusion that Ichthy- 
osaurus possessed a terminal tegumentary and ligamentous vertical 
caudal fin. By the weight of this fin, or by the force of the waves 
beating upon its extended surface, the break of the tail was produced. 
In the restaurations of Ichthyosaurus the tail was figured unbroken, 
with a caudal fin extending symmetrically above and below in a vertical 
plane, and ending in a point at the end of the vertebral column. 
*OwEN, R.: Note on the dislocation of the tail at a certain point observable in 
the skeleton of many Ichthyosauri, Trans, Geol. Soc., 2d Ser., Vol. V., pp. 511-514, 
pl. 42. 
