OF THE GREAT AUK, OR GARFOWL. 329 



This (PI. LI. fig. I, III) is 1 inch 9 hnes long, inclusive of the magnum, and is confluent 

 with the fourth slender metacarpal (iv) at both ends, leaving an interosseous space 

 1 inch 1 line long and 2 lines wide. 



The proximal phalanx of the medius (in. i) is broader than the metacarpal, having 

 its ulnar border extended into a ridge and slightly produced beyond the distal articular 

 end. To this is joined a second phalanx (ib. 2 ), terminating, like that of the forefinger, 

 in a point. The length of the hand is 3 inches 6 lines. The broad and flattened general 

 character of the bones of the fore limb relate to the support of a surface in the 

 shortened wing adequate, as a fin, to strike the water with effect. 



§ 4. Pelvic Arch and Appendage. 



The pelvic arch has been described. Its appendage departs less from the general 

 ornithic type than does that of the scapular arch. 



The femur (PI. LI. fig. 1, 65; PI. LII. fig. 11), 2 inches 10 lines in length, shows 

 the usual extension of articular cartilage from the head to the upper part of the 

 neck and great trochanter, expanding upon the latter. The ligamentum teres is im- 

 planted in the upper part of the head. The trochanter does not rise to a higher level ; 

 the ridge at its fore part descends about 6 lines upon the bone, gradually subsiding ; 

 the back or outer side of the trochanter is broad and nearly flat ; the popliteal side of 

 the shaft of the proximal part is flattened, the rotular side is concave. The shaft soon 

 assumes a full elliptic transverse section, is very slightly bent, with the concavity 

 backward ; it slightly expands to the distal condyles. It has a large medullary cavity. 

 The rotular groove is wide, and is partially defined from the inteicondyloid or popliteal 

 groove, in which are the depressions for the crucial ligaments, The outer condyle has 

 the usual backward or popliteal production, vertically grooved for the compressed head 

 of the fibula. 



The tibia (PI. LI. fig. 1,66; PI. LII. fig. 12) is 5 inches 2 lines in length. The 

 proximal articular surface is but feebly defined ; the tibial or inner division is the 

 largest ; the fibular division is convex. The rotular process, of a triangular form, with 

 a base as broad as the tibia, rises half an inch above the articular surface, and sends off" 

 a procnemial (PI. LII. fig. 12, p) and an ectocnemial (e) ridge. The latter is short, 

 thick, and angular ; the former is long, thin, and also forms a low angle. The proximal 

 part of the shaft of the tibia is trihedral : there is an oblong tuberosity on the inner or 

 tibial side. Eight lines below the articular surface commences the fibular ridge, which 

 has a similar extent ; the fibula is anchylosed therewith in the skeleton from the 

 mummified specimen, but not in the bones of the Great Auk sent to me by Mr. John 

 Hancock. After an interval of separation of about 3 lines, the fibula (ib. 6?) coalesces 

 in both specimens with the tibia, and can be traced to within an inch of the distal end 

 of the bone. The shaft of the tibia soon acquires a form giving an ellipse in transverse 

 section, elongated from side to side ; it very gradually diminishes to within an inch of 



