Haast.— Notes on Mesoplodon floweri. 449 
length, they become more constricted, and assume a prismoid shape, after 
which they flatten and gain again in breadth, their terminal end being, 
however, narrower. 
The eighth and ninth ribs, which have only one articulating surface 
for their junction with the transverse process, have the same form as the 
foregoing, if we imagine their heads and necks removed. 
The tenth rib is flattened throughout; it has also only one articulating 
surface, and, at its posterior end, runs out to a point. 
The greatest length of each rib, measured in a straight line, is :— 
Me ee ee 
Second ... ae iss m xn were Eon 
Thu < i ee Bb. de w 2 POU 
Fourth ... s ve jas he wu. a ARD 
Euh -a ii um Da ia w S TUE 
PU . 2 480 
Seventh ... 2 460 
Eighth 2 850 
mih .. ize AD ts ps s um OR UD 
WONG wai ae . 0 46°25 
Sternum (Pl. XXVI., Fig. 5). 
The sternum consists of four prineipal segments, of which the fourth 
and smallest is separated into a left and right portion by a division in the 
centre, and which apparently would not have disappeared by anchylosis in 
a still more aged state of the skeleton. The first segment is the largest 
and broadest; it is without a keel, but is well rounded towards the central 
line. There is a deep exeavation on its upper, and a shallower one on its 
lower portion. Similar exeavations exist in the three other segments, by 
which three fenestre of a rounded shape are formed. There are five 
articulating surfaces on each side for the sternal ribs: the first near the 
upper portion of the first segment, the second at the junction of the first 
and second segments, the third at the junction of the second and third 
segments, the fourth at the junction of the third and fourth segments, and 
the fifth at each side of the fourth segment on its lower portion. 
Pectoral Limb, 
The scapula is remarkably flat and without prominent ridges, so that 
there is scarcely any sign of the post-scapular fossa. In form it resembles 
that of Mesoplodon sowerbiensis. The acromium is broad, and has an upward 
slope in its anterior portion ; the coracoid is flat and narrow, but widens 
considerably at its extremity, where it assumes a prismoid form. 
r2 
