PankER.—Notes on Balrenoptera musculus ? 9 
narrower at their anterior ends. Judging from published figures also, the 
upper surfaces of the bones seem to be unusually strongly ridged. Each 
has a prominent ridge along its inner border, then a somewhat triangular 
depression with forward apex, then a strong oblique ridge passing from 
&bout the middle of the posterior border of the bone to its antero-internal 
angle; from the outer edge of this ridge the bone slopes downwards, end- 
ing externally in a low ridge. 
2. The Jugals (fig. 8).—1 have not succeeded in.finding any special 
description or figure of the jugal ; but, judging from the appearance of the 
bone as shown in Van Beneden and Gervais's figures of the skull of 
B. musculus," that of the present specimen appears to be broader at its 
anterior and narrower at its posterior end, than usual, and to be somewhat 
strongly curved. Owing to the absence of separate figures of this bone and 
of the lacrymal (fig. 2), in the works at my disposal, I have thought it 
advisable to give figures of both, drawn to the same scale as the nasals. 
8. Breadth of Beak.—The proportion of the breadth of the beak to the 
length of the skull seems to be smaller than usual, being as 17:5: 100. In 
six skeletons measured by Flower, the proportion varies from 18 : 100 to 
21: 100. 
4, Vertebral Column.—The places at which the various dimensions of 
the vertebre reach their maximum, differ slightly from those recorded by 
Murie in the Rosherville Gardens specimen,t and the relative dimensions of 
the vertebre themselves show certain differences, but I do not consider 
these of sufficient importance to be recorded, except in the table of 
measurements. 
5. The Sternum (fig. 4).—This differs from the corresponding bone in 
all the skeletons of B. musculus of which I have seen descriptions, in 
being longer than broad, like that of B. rostrata. The length is to the 
breadth as 16:13, while, in other specimens measured, the proportion is 
about 16:20. The antero-lateral edges and the lateral angles were, how- 
ever, evidently edged with cartilage, so that the breadth was probably 
considerably greater in the fresh state. 
Van Beneden and Gervais give the excess of breadth over length in B. 
musculus as a character of specific importance. Von Haast also figures the 
sternum of B. australis, which he seems to think is probably identical with 
B. musculus, as broader than long,{ and the same is the case with a speci- 
men of the same species described by Hector. || 
* Op. cit., pl. xii. and xiii., figs. 11 and 12. 1 P.Z.8., 1865, p. 206. 
1 “ Notes on a Skeleton of Balenoptera australis, etc.,” Proc. Zool. Soc., 1883, p. 592, 
|| “ Notes on New Zealand Whales,” Trans. N.Z. Inst., vol. vii., 1874, p. 251. 
