76 
THE KACES OF THE GALAPAGOS, 
is much less obtuse than in T. elej)liantoj)us (about 100°) ; the body of the scapula is 
compressed, elliptical, with both its anterior and posterior sides equally convex ; a 
transverse section through its middle would be represented by the figure of a greatly 
elongate O. The shaft of the acromium is trihedral, with the edges rounded, and with 
the extremity compressed and slightly dilated. The coracoid is not ankylosed to the 
scapula ; and its proximal part (neck) is singularly dilated, and very much broader than 
the corresponding part in T. elephantopus. In fact the diiferences in the scapularies of 
these two species are so great, that they alone would clearly prove their specific 
distinctness. 
T. dephantopus, T. vicina, 
790 millims. long. 840 millims. long. 
millim. millim. 
Length of scapula (measured from the coracoid suture) ... 200 188 
Circumference in the middle of the shaft 75 75 
Longitudinal diameter o£ glenoid cavity 50 55 
Length of coracoid 86 83 
Greatest width of coracoid 70 74 
Least width of neck of coracoid 20 33 
Length of acromium 84 78 
The humerus is so similar to that of T. elephantopus (and consequently very dis- 
similar to that of T. epMppiuin) that no detailed description is needed ; but, as in the 
latter species, the canal for the blood-vessels on the radial edge, close to the elbow- 
joint, is deep and partly open. 
T. . 
elephantopus. 
T. epJdppium. 
T. vicina. 
millim. 
millim. 
millim. 
Length of humerus 
216 
235 
225 
Circumference of the narrowest part of shaft 
89 
91 
95 
Longest diameter of the head 
40 
40 
40 
Shortest diameter of the head 
37 
35 
38 
Extreme breadth between the condyles 
82 
82 
81 
The bones of t\\e forearm (Plate LIV. fig. D) are also shorter than those of T. ephip- 
pium, more similar to those of T. elephantopus, particularly with regard to the deeply 
emarginate radial edge of the ulna. Both bones are smooth, without prominent ridges 
or tuberosities. The ulna is twisted round its longitudinal axis, so that the transverse 
diameters of its proximal and distal dilatations would intersect each other at an angle 
of about 45"". The olecranon is not much developed. The articular facet of the radius 
for the articulation of the humerus is a rectangular triangle, with the point directed 
backwards, and the shortest side in front. 
