51 G Mr. E. I. Pocock on (he Preorhital Pit in the 



shelving nasals. The lateral palatal grooves are deep in the 

 adult. Third upper molar without any closed triangles and 

 ■with the middle outer triangle muoli reduced ; this tooth 

 shows therefore the characteristic pattern of the daodecim- 

 costdtus group. 



Four inguinal mainiiue. — Five foot-pads on the hind sole. 



Dimensions [in miirwi.), iaken from sjtirit -specimens. 



Head and 

 body. 

 R.M. uo. 9o.4.2f).") (adult <5). . . . 84 

 B.M. no. 04.3.19.8 (young J) . . 73 



Dimensions of the Skull. 



94.1.1.16. 94.1.1.17. 94.3.19.7. 94.3.19.8. 



y^. ad.$. $ jun. 2 i""- J .iun. 



Greatest length 229 2Uo 204 21 



Basilar longth 19-8 .. 17-7 18 



Length of nasals 6 6-o 5*8 



„ upper molar series . 6 5*5 5''3 6'5 



„ lower „ „ . 5-9 .5-4 67 5-4 



Zygomatic breadth 14 12-6 12-4 12-5 



Mastoid breadth 10 . . 97 10-2 



Height at occipital 6 . . 6'3 5'6 



Height between bulla and 



occipital 8 7 7-5 87 



Fronto-palatal height 8 68 7 7-5 



Type specimen, B.M. no. 94. 1. 1. 16, young adult $ 

 (spirit-specimen). Yillalva, Lugo, Galicia (iN.W. Spain). 



LXVII. — On the Preorhital Pit in the Skulls of Domestic 

 Horses and Qaaycjas. By E. I. Pocock, F.L.S., F.Z.S., 



Superintendent of the Zoological Society's Cxardens. 



In the * Annals ' for last November (p. 317), when criticising 

 ISIr. Lydekkcr's statements and opinions with regard to the 

 presence of a preorhital pit upon the skulls of horses and 

 quaggas and the systematic value claimed for it, I remarked 

 that its known occurrence in two true quaggas^ skulls would 

 to a certain extent justify a provisional generalisation as 

 to its constancy in that animal, were it not that this pit 

 belongs to the category of characters which are likely to 

 appear sporadically as atavisms and are therefore, from the 

 systematic standpoint, open to suspicion on the score of 

 inconstancv; and I added that ''such characters are of 



