274 MESSRS. O. THOMAS AND H. SCHWANN ON [Apr. 18, 



Incisors with tlieir notch shallow, situated in a comparatively 

 broad flattening of the front surface of the tooth. Large upper 

 molars and premolars (shown in Lyon's pi. xci. fig. 8) with the 

 uncrenulated anterior enamel- w^all of the posterior lamina of each 

 tooth extending neai'ly halfway across the tooth towards the outer 

 border ; crenulated adjoining outer parts of the enamel- walls of 

 the two laminge subeqvial in development, strongly crenulated. 

 Anterior lower premolar with its anterioi* enamel-wall deeply 

 crenulated. Thin front wall of the hinder lamina of each lower 

 tooth (apart from nig) very strongly crenulated. 



In P. crassicaudatios, on the other hand, the skull is small, more 

 slenderly built, the muzzle narrow, and the frontal profile flat. 

 Supraorbital wings larger, their hinder edge closer to the brain- 

 case. Anteilor shoulder of zygoma small. Palatal foramina large, 

 evenly broadened to their hinder edge, widely open behind, with 

 slanting and scarcely ridged margins which do not hide the walls 

 of the nasal chamber below. Sphenoid openings comparatively 

 large. BuUse fairly large, not surpassed by the small paroccipital 

 processes. 



Incisors with a comparatively deep sharj)ly defined notch 

 dividing the two strongly convex poi'tions of the anterior siu^face. 

 Large upper cheek-teeth with the uncrenulated pai't of the 

 anterior enamel-wall of their posterior lamina? extending only 

 about a third across the tooth ; in the ci'enulated part of the 

 enamel-walls the hinder wall of the anterior laniin?e is considerably 

 more developed than the front one of the posterior, and all are less 

 strongly crenulated than in P. ruclcli. Anterior lower premolar 

 simply notched in fi-ont. Front wall of the hinder lamina of the 

 large lower cheek-teeth scarcely crenulated. 



It will thus be seen that while externally P. ruddi is very like 

 P. crassicaudattis, the difierences in the skull are so considerable 

 that almost any part of the skull, or any single tooth, can be 

 readily assigned to one or the other. 



Dimensions of the type of P. ruddi (measured in the flesh) : — 

 Head and body 482 mm. ; tail 52 ; hind foot 99 ; ear 98. (The 

 hind foot of P. crassiccmdatus is seldom over 80 mm.) 



Skull — greatest length 92 ; basilar length 72 ; zygomatic breadth 

 40; nasals 44x22; interorbital breadth 16; intertemporal 

 breadth 13*3; diastema 30; palatal foramina 26 X 8"5 ; palatal 

 bridge 9"7. 



Corresponding measurements of two members of the P. crassi- 

 ccmdatus group are to be found in Thomas's descriptions of P. c. 

 nyikce and P. c. curryi^ . 



Hah. Sibudeni, Zululand. Alt. 1100 m. 



Type. Male. B.M. no. 4.5.1.78. 



The discoveiy and elucidation of this remarkably fine hare is a 

 vahiable result of Mi'. Rudd's exploration of S. Africa, and one of 

 special interest, as it forms a second species of the recently erected 

 genus Pronolagus. 



* Ami. Mag. X. H. (7) x. pp. 245-6 (1902). 



