220 MR. W. P. PYCRAFT ON THE MORPHOLOGY AND 
Apteryx, in the form and position of its coracoid grooves, resembles Rhea more 
closely than any other group. Like Rhea they are widely separated by a deeply 
concave median portion of the anterior border of the sternal plate. The groove lies at 
the base of the anterior lateral process. It is very short, and has a conspicuously 
projecting lower lip. 
The sternal plate differs from that of all the foregoing in being non-pneumatic. 
Its breadth exceeds its length. Posterior lateral processes are well marked, and 
divided one from another and a median process by a pair of notches. The articular 
surfaces for the ribs, as in Struthio, extend along the greater part of the lateral 
sternal wall. 
Occasionally, ¢. g.,in an A. australis described by Owen, the sternum was fensterated. 
Beddard describes a pair in A. australis mantelli. In another of this species were a 
pair “ of pin-hole size.” 
Parker directs attention to a distinct keel on the sterna of A. australis mantelli. 
As Beddard remarks, though not easy to see, this is readily felt. He found traces in 
A. haastii, and I think to these we might add A. oweni. A similar keel, and much 
more easily seen, often occurs on the sterna of Struthio. 
The researches of T. J. Parker and Beddard, which I am able to confirm, show that 
no really reliable specific characters can be obtained from the sternum of Apteryz. 
Roughly, as Parker and Beddard point out, “in A. australis the length of the 
corpus sterni appears to be constantly more than half its breadth.” 
In A. australis mantelli “ the length of the corpus sterni is—often considerably— 
less than half its breadth.” 
In A. oweni ‘the length of the body is less than half its breadth.” 
A, haastii, according to Beddard, belongs to the same category as the last two. 
The emargination of the anterior border of the sternal plate and the length of the 
metasternal and posterior lateral processes vary so much that they cannot be relied 
upon as specific characters. 
The anterior emargination of the sternum seems to offer at least one more or less 
constant character. Thus, both Parker and Beddard agree that this is usually a 
semicircular incision, but that A. australis mantelli may be distinguished “ from 
A. australis by the greater depth of the emargination in the former subspecies.” 
Mr. Beddard finds at least one exception to this, in A. australis mantelli. Parker 
points out that “in A. oweni. . .. the emargination of the anterior border is slightly 
sinuous, each side presenting a sigmoid curvature.” There would appear to be no 
exceptions to this rule. 
The sternum of Dinornithide more closely resembles that of Apterya than of any 
other form herein described. From this it differs in the following points:—That 
portion of the anterior border of the sternal plate which separates the coracoid grooves 
in Apteryx is in the present group perfectly straight instead of hollow. Furthermore, 
