172 SECTION B. VERTEBRATA. 



SECTION B. VERTEBRATA. 



Friday, 26 August, at 2 p.m. 

 Chairman, Prof. Newton. 



I. H.EMATOPOIETIC PROCESSES IN THE PLACENTA. 

 By Prof. A. A. W. Hubrecht. 



Discussion by Messrs. Sedgwick, Gadow, Bles. 



Reply by Prof. Hubrecht. 



Professor Hubrecht's paper is printed in full in the Appendix 

 under the title, — " Ueber die Entwickelung der Placenta von 

 Tarsius und Tupaja nebst Bemerkungen iiber deren Bedeutung 

 als haematopoietische Organe." 



2. On Pliohyrax Kruppii Osborn, a fossil Hyracoid, 

 FROM Samos, Lower Pliocene, in the Stuttgart Col- 

 lection. A NEW TYPE, AND THE FIRST KNOWN TERTIARY 

 Hyracoid. (With Plate 2.) 



By Prof. H. F. Osborn. 



In the Museum of Stuttgart is a collection from the Lower 

 Pliocene of Samos, presented in 1895 by Herr Krupp, the well- 

 known manufacturer. Its most unique feature is the facial portion 

 of the skull of the first extinct member of the order Hyracoidea 

 known to science. This type has been mentioned by Roger' and 

 Smith Woodward- as Hyrax Kruppii, a name provisionally assigned 

 by Professor Eberhard Fraas in honour of the donor. During my 

 visit to Stuttgart in July, 1898, Professor Fraas with rare generosity 

 placed the type in my hands for description, and we agreed that it 

 was worthy of presentation before the Zoological Congress. 



It proves to be not only a new species, but a new genus, which 

 may be termed Pliohyt'ax, and possibly the representative of a new 

 family, PlioJiyvacidae, of the Hyracoidea, an order which has been 

 distinguished hitherto by our total ignorance of its ancestral forms. 



The skull as here shown in life-size photographs kindly taken 

 under the direction of Professor Fraas (see Plate 2) is more than 

 twice the size of the largest living Hyrax. It is further distin- 

 guished by three very important characters : 



1. The elevated union of the premaxills anteriorly, thus 

 elevating the anterior nares. (Compare Figs. 2 and 4.) 



2. The elevated position of the orbits. 



^ Verzeichniss d. bisher bekannten fossilen Saugethiere. Augsburg, 1896. 

 2 Vertebrate Paleontology, 1898, p. 292. 



