PROFESSOR FLOWER ON THE RECENT ZIPHIOID WHALES. 221 
In general arrangement these foramina correspond very closely with those of Hypero- 
odon. In the Sperm-Whale the greater massiveness of the cranial walls, compared 
with the brain-cavity, and the consequent greater distance that has to be traversed by 
the nerve-canals, causes some alteration in the condition of the foramina, several (as in 
the case of that for the seventh and eighth nerves) more completely coalescing into a 
single aperture, at least at their cerebral ends, than in the smaller-headed Ziphioids. 
Dimensions of the Skull. 
inches. 
Extreme length of cranium . . . 5 pul tice asi + 
Length of rostrum (from the apex of the Ree tiariltee to the middle af 
a line drawn between the anteorbital notches) . . . . . . . . 362 
Anterior end of vomer to anterior end of premaxille. . . . . . . 136 
From middle of hinder edge of palate bara by pterygoid bones) to 
end of premaxille . . . 5h vosy aytoee Fe LOR 
Greatest height of skull, from of eee to ones eae 4 wiereeoiie 21 
Greatest breadth, across postorbital processes of frontals . . . . . 27 
Breadth across zygomatic processes of squamosals. . . . . . « . 26°4 
Breadth between outer borders of suprafrontal processes of maxille . . 24:6 
beeen OUCIDITALCOMMV ICR go rie lk sh ek Rw fa Dd ea LD 
Bee IO OT RINT TRE a a ea US lh ca ln cy oir 
(Fae) Pr PRGe Tor ie aac 01! ee a ao Pee nr aaa ee See Pew) 
Breadth of exoccipitals . . . ie oi we En i ice cr eta) 
Breadth of base of rostrum ener Hetior of Sener notches). . 15-7 
ECHO ORIN hy unc ha De eo ne eno hee em) 
Weral Danes, ANCerO-POSterIOT Vem eG ya ia inks a five mye eat at fishy wn sh 
Nasal bones, greatest breadth of thetwo. . ...... +... 4 
Anterior nares, greatest width of the two. . . . . . +...» 2g 
Breadth between outer borders of premaxille opposite nares . . . . 66 
Breadth between outer borders of RRR, at their widest part, in 
front of the nares. . ens : ae toe 
Breadth between outer baeien of Pee neal at Paddle ae rostrum . . 3°6 
Mandible ——Length, of ramisie 5 ie ee een Le We Me) dante Be £O 
Meno GhboresyUIpMVSIS) pe yt se vy Ne: och Bo Su ache cig ise hie 
Vertical height of ramus at coronoid process ee 83 
Apex of mandible projecting beyond apex of rostrum . . 27 
The rami of the mandible are not ankylosed at the symphysis. They are more 
massive in form and of a denser substance than in Hyperoodon, especially near the 
symphysis, corresponding with the greater development of the teeth. A slight irre- 
gular groove, with numerous minute vascular canals opening into it, extends along the 
2K2 
