226 Proceedings of the Royal Physical Society. 



ligamenta alaria are homologous with the transverse liga- 

 ment. 



The large portion of the cup on the anterior aspect of the 

 chelonian atlas, which is formed by the expanded inferior 

 extremities of the arch, illustrates very well the unity of 

 plan upon which the articular surfaces of the atlas are 

 formed in animals having one occipital condyle, and those 

 which have two. This will be seen by comparing the wood- 

 cuts above. 



When, in the human subject, a process of bone passes up 

 from the arch of the atlas, to meet the superior articular 

 surface, and convert the groove for the nerve and vertebral 

 artery into a foramen, the process in question is a true 

 oblique process. If, in addition, we were to imagine the 

 tip of the transverse process thickened and projecting up- 

 wards to meet the superior articular surface, we should then 

 have presented to us the condition of parts found in the pig 

 and the sheep. 



IV. Ornithological Notes. By John Alexander Smith, M.D. 

 (Specimens exhibited.) 

 (1.) Falco islandicus, (Lath). The Gyrfalcon. 



This specimen of Gyrfalcon was killed about the middle 

 of last October by James Maclean, gamekeeper to Sir 

 John Orde, on his property near Loch Maddy, in North 

 Uist. Tne bird is probably a young male, and a very 

 fine specimen of this extremely rare and occasional visitor, 

 — no instance of its breeding in Scotland, he believed, was 

 on record. It measured in length 22| inches ; the wing, 

 from flexure to point of primaries, 15 inches. The head 

 white, with longitudinal stripes of brown ; the upper parts 

 of body brown, tinged with grey ; the feathers partially 

 edged and spotted on the margins with white. Below 

 white, with longitudinal spots of brown ; the flanks white, 

 broadly dashed with brown. In the wings, the second pri- 

 mary is the longest, the first and third being nearly equal. 

 Tail brown, barred with white, the white mottled with 

 brown. 



Another specimen of this falcon was killed by Maclean 



