2 
regard the proximal element of the digit as a trapezium, the 
scapho-carpal does not represent all the carpalia, and the pollex 
becomes of normal constitution, possessing its carpal, metacarpal 
segments and two phalanges. 
There seems, in fact, to be a marked tendency to synostosis of 
the bones of the manus, for in my original specimen it certainly 
appeared as if the elements of the fifth digit were reduced to 
two, a proximal, described as a metacarpal which (with the pisi- 
form) supported the ungual phalanx. In Professor Wilson’s 
specimen a division of this supposed metacarpal into two is cer- 
tainly, if indistinctly, indicated. This arrangement, of course, 
provides for the fifth digit a metacarpal and two phalangeal seg- 
ments. No trace of such division, however, was visible in my 
original specimen, or in another which I have since examined. 
In the latter specimen there is complete synostosis of the 
ungual phalanges of the pollex and index of one manus, and 
almost complete fusion of their respective claws (fig. 2). On the 
other side no such fusion occurs. As further evidence of this 
tendency to synostosis in other parts of the skeleton, beyond the 
facts already mentioned, it is worthy of note that, in Professor 
Wilson’s specimen, the styloid process of the radius is completely 
separate, whereas it is firmly ankylosed in my two skeletons. So 
also in the first rib he finds on one side well-marked evidence of 
a synchondrosis between the broad expanded sternal end and the 
more rod-like vertebral moiety. This is not nearly so well 
marked on the other side, and is not perceptible at all in my 
specimens. This synchondrosis evidently indicates the fusion of 
two distinct osseous elements, of which the ventral doubtless 
represents a sternal rib. 
EXPLANATION OF PLATE I. 
FIGURES. 
1. Notoryctes typhlops. Right manus, palmar aspect (x 4). 
al, ulna. 
rad, radius. 
ty, styloid process of radius (separable). 
sc, scapho-carpal. 
tr, trapezium. 
met (1), Metacarpal of pollex. 
met (2), ** second digit. 
met (3), se FES ol Ware (ea 
ph prox, proximal phalanx of pollex. 
ph dist, distal phalanx of pollex. 
p s, palmar sesamoid. 
Pp, pisiform. 
u, ungual phalanx of fifth digit. 
2. Notoryctes typhlops. Right manus, palmar aspect (another specimen). 
a, ankylosed ungual phalanges of pollex and second digit. 
b, claws similarly fused. 
Other references the same as in fig. 1. 
