336 Mr. F. E. Beddard on the 



stated at the end of this paper (p. 340), with the addition of 

 otherSj of which I can find no particular description in the 

 memoirs cited. 



1. Skull. — The most obvious characters which distinguish 

 the skull of Striae from that of the remaining genera have 

 been pointed out by Milne-Edwards*; they are, firstly, the 

 greatly elongated and narrow form of the skull in Strix 

 contrasted with the wide short skull of other types ; secondly, 

 the relatively great thickness of the bones which make up the 

 interorbital septum in Stris as compared with the extremely 

 thin interorbital septum of other Owls. 



I find by a series of measurements of the skulls of the 

 following types : — 



Strix flammea, Bubo beugalensis, 



Strix sp., Syrnliim indranee, 



Asio mexicauus, Syriiium woudfordi, 



Speotyto cuiiicalaria, Ketupa javauica, 



Athene noctua, Sceloglaux albifacies, 



Bubo maximus, Nyctea nivea, 



that while Strlv has the narrowest skull (the proportion of 

 greatest breadth to length being in Strix &]). inc. as 37*5 : G.2, 

 in Strix flammea 36 : 56), the other genera show a progressive 

 widening of the skull; this culminates in Speotyto cunicu- 

 larla, where the brcadtn is to the length as 37 : 38. I do 

 not give the exact measurements in the other species men- 

 tioned in the present list for the reason that such a table of 

 measurements would only be of value if it embraced the 

 results of a study of a larger number of species and of indi- 

 viduals. I may state^ however^ that I have examined a large 

 number of Owls' skulls in the British-Museum collection, 

 including those of two other species of Strix (viz. S. perlata 

 and >S^. delicatula) , and in no case do I find so long and narrow 

 a skull as in the genus Strix. It may be worth while men- 

 tioning that Sceloylaux albifacies has a skull which comes 

 nearer to that of Strix in its relative proportions than do the 

 skulls of many other genera. The reason which leads me to 



* Nniiv. Arch. &c. p. 189. 



