134 SHUFELDT. [Vol. XVII. 



characterized in the main only by its darker plumage, will 

 present about the same structure in the cranium as the palaeo- 

 arctic 6". lapponictmi, is evident. ^ 



This is further shown in two figures, which are given in 

 Baird, Brewer, and Ridgway, A History of North- American 

 Birds, Vol. Ill, pp. 99, 100. 



Finally, Syrnium uralense, the third species having an asym- 

 metrical cranium, is represented in the eastern part of the 

 palaeo-arctic region (Japan) by a similar race or subspecies, 

 S. rufescens (Temm. and Schl.), 1850,^ which is smaller and 

 darker in plumage than the type species, but nothing is known 

 of the structure of its cranium. 



It is not improbable that there are still other species of the 

 genus Syrnium that will furnish examples of cranial asymmetry. 

 Of this genus, Sharpe has in his Catalogue of Birds, British 

 Museum, Vol. II, 1875, described twenty-seven species, besides 

 various subspecies, to which are to be added two others, old 

 species that of late years have been transferred into this 

 genus. 



I. SuRNiA FUNEREA (Linn.), 1766. 



(Plate XV, Figs. 1-3.) 



Both the auricular openings and the cranium are symmetrical, flap being 

 absent in the former. 



The skin-like auricular openings are of medium size, sym- 

 metrical, and comparatively lowly situated, inasmuch as their 

 upper edges barely ascend above the middle of the eye, the 

 lower reaching down to about the mandible. They are evenly 

 rounded above and below, perpendicular, and in an adult female 

 specimen (collected in West Aker, Christiania, Nov. 12, 1881) 

 measure 12 mm. in height and 9 mm. in breadth. There is no 

 evidence whatever of the presence of any dermal flaps, or of 

 any raised dermal folds about the margins. 



1 " One point of note is to be observed, however, and that is, in some species 

 of Syrnium the skull is symmetrical, while in some others asymmetrical distortion 

 to a moderate degree is observable. Of the first condition S. nebulosum is an 

 example, and of the latter, S. cinereum furnishes us an instance." (Shufeldt in 

 MSS., March 20, 1896.) — R. W. S. 



2 " Referred to as Strix rufescens in the text, and S. fuscescens on the plate." 



