PUBLICATIONS. 239 
In 1892 Dr. E. Fraas* described a specimen of Ichthyosaurus from 
Holzmaden, Wiirtemberg (Museum, Stuttgart), in which the whole skin 
of the animal was preserved. The fin proved to be quite large, sym- 
metrical, and of the same shape as that of the sharks, but the vertebree 
did not extend to the dorsal but to the ventral lobe of the fin, thus 
demonstrating that the dislocation in the tail was the natural condition. 
The same specimen showed that there existed a very large dorsal 
median fin, placed a little in front of the pelvic fins. The pectoral 
and pelvic fins were also beautifully preserved, and showed, what had 
been known already before, that the fleshy part of the paddles extended 
very much further backwards than the bony skeleton.? 
Nearly at the same time a splendid specimen of a tail fin of Ichthy- 
osaurus of very large size was found in the lithographic limestone of 
Solenhofen, and is now preserved in the Munich Museum; another 
tail fin from Holzmaden has gone to the Berlin Museum ; and a very 
complete specimen, showing the whole skin, has lately been secured 
from Mr. W. Hauff, Holzmaden, by the Museum of Freiburg (Switzer- 
land), for the sum of $750. In many specimens, which are now in the 
different museums, the skin could probably have been preserved, if 
anyone had thought of the existence of it. In the future it will be 
possible, by very great care. 
It is of very great interest that we know now the real structure of 
the fins of the Ichthyosauria. It is well known that the Ichthyosauria 
originated from land-living reptiles closely related to the Rhyn- 
chocephalia and Proganosauria;* that the fins have been gradually 
developed through the adaptation to marine life is clear ; it would be 
very interesting to find out whether the Triassic Ichthyosauria, in 
which the limbs are less specialized, show already the same structure in 
the tail as the forms from the Jurassic. 
We see that a very similar fin structure is developed in two groups 
of animals belonging to two entirely different classes. In the Sel- 
™Fraas E.: Uber einen neuen Fund von Ichthyosaurus in Wiirtemberg. Neues 
Jahrb. f. Min. 1892, pp. 87-90. 
* A very good photographic reproduction of the specimen is given by Fraas in 
Jahreshefte des Vereins f. vaterl. Naturkunde in Wiirtemberg, 1894. Taf. V. 
3G, Baur on the Morphology and Origin of the Ichthyopterygia. Am. Naturalist, 
1887, p. 837. 
Uber den Ursprung der Extremitaten der Ichthyopterygia. Vers. Oberrhein. Geol. 
Verein., 1887, Stuttgart, 4 p., 4 fig. 
