260 PROF. OWEN ON THE ANATOMY 
The head of the Apteryx is broad, slightly depressed, and very regularly convex above. 
The opening of the eyelids is situated immediately behind the vertical line touching the 
angle of the gape, and about three lines above that angle; it is 4 lines in length: the 
lower lid is most developed, as in other birds ; the upper one is fringed with a row of 
pretty stiff black cilia. The external auditory aperture is situated half an inch behind 
the eye, and is also a horizontal elliptical fissure, 4 lines in length, formed by a tumid 
fold of integument, and defended by short and strong ciliiform plumelets. 
The weight of the male Apteryx transmitted to me by Mr. Bennett, and which had 
all the appearances of a mature bird, was, without its plumage, 3 lbs. 6 oz. 12 dr. avoir- 
dupoise ; its total length, from the extremity of the beak to that of the outstretched 
leg, was 28 inches and 8 lines ; from the extremity of the beak to that of the coccyz, 
19 inches ; the length of the trunk was 7 inches ; the length of the neck, head and beak 
included, was 12 inches; that of the beak, from the gape to the point, 4 inches and 8 
lines ; the breadth of the beak at the gape, 1 inch; its depth or vertical diameter at the 
same part, 7 lines. The different proportions of these latter dimensions to the length 
of the beak, as compared with those in the specimen described by Dr. Shaw and Mr. 
Yarrell, are considerable ; the length of the beak in that specimen, from the gape to the 
point, being 6 inches and three quarters. This difference has led me to compare to- 
gether very minutely the different specimens of the Apteryx at present in the Museum 
of the Zoological Society and in that of Mr. Gould, particularly with reference to the 
condition of the beak. Of these specimens, which are five in number, two present 
proportions of the beak, corresponding nearly with those of the originally described 
specimen'; the other three have the shorter and weaker beak of the male Apteryx here 
described*. The following are the admeasurements taken from these specimens : 
LENGTH OF THE BEAK FROM THE GAPE TO THE POINT. 
Dr. Shaw’s. Mr. Gould’s. Zool. Soc. No. 1. Mr. Bennett’s Male. | Zool. Soc. No. 2. Zool. Soc. No. 3. 
Inches. Lines. Inches. Lines. Inches. Lines. Inches. Lines. Inches. Lines. Inches. Lines. 
6 | 8 6 6 | 3 4 | 8 4 | 6 4 | 6 
Thus we have a series of three longer-billed and three shorter-billed specimens of the 
Apteryx : dissection has shown one of the latter to be of the maie sex ; it remains to be 
proved whether the longer bill is peculiar to the female. At present it may be ques- 
tionable whether this difference be dependent on a difference of age, of sex, or of spe- 
cies. But I would observe that on the first hypothesis it might be expected that the 
bill would have been smaller in all its dimensions, and that there would have been a 
want of correspondence in the size of other parts, as of the feet®. This, however, is 
not the case, but on the contrary, the very close correspondence between the short- and 
long-billed specimens in all other particulars indicates the difference in the length of 
the beak to be not a specific one. If, therefore, it should actually be found to be a 
sexual character, it will form another anomaly in the organization of the Apteryx ; for 
1 Pl. XLVII. Fig. 1. 2 Pl. XLVII. Fig. 2. 
3 The general dimensions of Dr. Shaw’s specimen being taken from a dried and stuffed skin are liable to in- 
accuracy ; Dr. Shaw assigns to it, from the tip of the bill to the extremity of the body, about 30 inches. 
