394 Mr. R. Lydekker on 



tarso-metatarsuSj in which the lateral compression of the 

 shaft is but slight^ and its second trochlea only moderately 

 reflected. In this family remains of the Great Auk {Alca 

 impennis) have been found in superficial deposits in the 

 Cleadon Hills, Durham, and likewise at Oronsay and Caith- 

 ness, in Scotland, while the " kitchen-middens " of Caithness 

 have also yielded remains of the Razor-bill {A. torda). The 

 extreme shortness, width, and strong curvature of the femur 

 of the Colymhid(e, the production of the patella into a long 

 spine ankylosed to the tibia, and the excessive lateral com- 

 pression of the comparatively long and slender tarso-meta- 

 tarsus, in which the small second trochlea is so much reflected 

 as to become almost behind the third, suffice to distinguish 

 them very widely from the corresponding bones of any other 

 birds. In this family remains of the Red-throated Diver 

 {Colymbus septentrionalis) have been obtained from Shandon 

 cave, Co. Waterford, and also from the river-deposit of 

 Mundesley, Norfolk, which is of later age than the Forest- 

 bed. Bones of the Crested Grebe [Podiceps cristatus) , which 

 was formerly abundant in the " broads " of Norfolk and the 

 fens of Lincolnshire, have been recorded by M. Milne- 

 Edwards from the fen-deposits of Cambridgeshire. 



II. Birds of the Pliocene. 



If we exclude the Norfolk Forest-bed from the Pliocene, 

 only two species of birds have been recorded from these de- 

 posits in Britain. 



Tubinares. — One of the most unexpected " finds " in the 

 Red Crag of Suffolk was the tarso-metatarsus and one phalan- 

 geal of the foot of a species of Albatross {Diomedea) . The 

 tarso-raetatarsus of the Albatross is a very characteristic 

 bone, somewhat smaller and relatively more slender than 

 that of a Swan; from which it is distinguished by the more 

 equal size of the three distal trochlese, the second of which is 

 only slightly shorter than the fourth, and is but little reflected, 

 while the foramen between the third and fourth is situated 

 much higher up than in the Anseres. Moreover, the front 

 surface is distinctly grooved, and there is no closed tube at 



