Dr. J. E. CJray on the Madagascar Wn-cr-Uorj. 4/) 



Localities. Ijiniekllns (Jld Quarry, near Limekilns House, 

 near East Kilbride, from shale between the first and second 

 limestones of the Calderwood series, Lower Carboniferous 

 Limestone group; Calderside Old Quarry, near East Kilbride, 

 from a similar geological horizon : collected by ^Ir. .James 

 Bennie. Mousewater, opposite Lambcatch, near Wilsontown, 

 from shale between two thin limestones of the Lower Carbo- 

 niferous Limestone group ; quarry near Ilillhead, near Wil- 

 sontown, from shale over the Guildhousc Limestone, Lower 

 Carboniferous Limestone group : collected by ^Ir. A. Macco- 

 nochie (collection of the Geological Survey of Scotland). 



EXPLANATION OF PLATE IV. B. 

 [The fig^ures are all considei-ably enlarged.] 



Fig. 1. Hyphasmoporn Bnskii, a bifurcating stem, showing the longitu- 

 dinal series of cell-depressions, with a peculiar swelling of the 

 interstitial surface. 



Fig. 2. The same. In this specimen are visible a few of the true cell- 

 orifices. 



Fig. 3. The same, showing the opposite face or interstitial zone, with its 

 single row of cell-depressions. 



Fig. 4. The same, a similar specimen to the last, but the branches with 

 a wider angle of bimrcation. 



V. — On the Madagascar River-Hog (Potamochoerus), and on 

 the Skulls of the three Species of the Genus. By Dr. 

 J. E. Gray, F.R.S. &c. 



[Plate IV. A.] 



Flacourt, in his ' History of Madagascar,' notices a wild 

 boar in that island ; and D'Aubenton, in his additions to 

 Buffon's ' Hist. Xat.' xiv. p. 390, describes a dry head of a 

 " sanglier de Madagascar " in the Cabinet of Paris, which he 

 says is that of a "cochon de Siam ;" but by his description it 

 is evidently that of a river-hog {Potamochoerus). I noticed it 

 as a species of that genus in ^ Proc. Zool. Soc' 1868, p. 38, 

 more especially as Mr. Sclater informed me that there was 

 a living specimen of the animal from ^ladagascar in the 

 Garden of Plants at Paris ; and in the ' Catalogue of Car- 

 nivorous, Pachydermatous, and Edentate Animals in the 

 British Museum,' 1869, p. 344, I named it Potamochoerus 

 madagascarien.fisj observing that I was not aware of any spe- 

 cimen in this country. I now find, which had escaped me 



