1886.] THE INTERVKRTEBRAL DISK OF THE AXIS IN MAN. 337 



11. Sterna MELANAUCHEN, Temm. 



[No. 8. d". October 9th, 1885. Eye black. 



Common. I have seen this bird pursued by the Noddy Tern, 

 just as they themselves are pursued by the Frigate-bird.] 



It would be interesting to know if this species breeds in Diego 

 Garcia, because, if so, the locality would be the furthest S.W. as yet 

 recorded. 



12. Sterna fuliginosa, Linn. 



[No. 7. $. October 8th, 1885. Eye black. Very common. 



These birds were laying when I arrived on Sept. 15, and single 

 epgs were scattered on the bare ground. The negroes soon took 

 all the eggs, and I could not make observations on the breeding.] 



13. GyGIS CANDIDA (Gm). 



[No. 3. c? . Sept. 25th, 1885. 



Very common, perching in the cocoa-nut trees, and laying a single 

 egg in the axils of the leaves, as described by Darwin in his ' Journal 

 of Researches.'] 



14. Angus stolidus (Linn.). 



[No. 5.$. October 2nd, 1885. Eye black. 



Common on the island. It constructs a large rough nest of a 

 heap of sticks and leaves, in the fork of a tree or bush, and on this 

 it lays one egg, upon which it sits.] 



[A bird called by the inhabitants the "Mangeur des Poules " was 

 said to visit the island frequently during the N.W. monsoons, but 

 I never saw one. Perhaps it may be Tinnuneulus panctatus, which 

 goes by the same name in Mauritius ; but if so it is not easy to see 

 why it should visit Diego Garcia only in the N.W. monsoons. 



" Fouquets " are abundant on the He des Vaches marines at 

 Peros Bauhos, and are said to have been seen on the He des Oiseaux, 

 Diego Garcia, but I never saw one. From the descriptions given me 

 they seem to be a species of burrowing Petrel.] 



3, On the Intervertebral Disk betvreen the Odontoid Process 

 and the Centrum of the Axis in Man. By J. Bland 

 Sutton, F.R.C.S.j Lecturer on Comparative Anatomy, 

 Middlesex Hospital Medical School. 



[Keceived May 29, 1886.] 



There are few bones in the human skeleton which can boast a 

 more extensive literature than the atlas and axis. Indeed so many 

 investigations have been made concerning their nature, and so much 

 has been written regarding the morphology of the first two vertebrae, 

 that most anatomists have abandoned them for more fertile regions 

 of the skeleton. Yet, in spite of this attention, a new fact in con- 

 nection with the axis has recently been disclosed by Prof. Cunningham 



