PROFESSOR OWEN ON INDIAN CETACEA. 85 
(Pls. XII., XTII., & XIV. fig. 2, 1) beneath the foramen magnum (ib. 0) is 8 lines: it is 
here convex vertically, and concave transversely, showing a width between the lower 
end of the occipital condyles (to which it probably contributed) of only 4 lines. These 
(Pl. XII. fig. 2, 2’) are more sessile than in Phocena brevirostris, being raised only 
by a linear border from the contiguous bone, except at their lower ends, which are 
rather more prominent: the long diameter of the condyle is 2” 2”, the greatest breadth 
1”: they are terminal, diverge as they ascend the sides of the foramen magnum, which 
is widest opposite their upper ends: the outer border of the condyle is more convex than 
the inner one. The foramen magnum is oval, with the larger end upward and not 
notched: the aspect of the plane of the aperture is backward and a little upward: in 
Physeter macrocephalus (Pl. XIV. fig. 2, 0) it is more upward than backward. The 
ex- (2) and superoccipital (3,3') plate inclines from below, upward, outward, and 
forward, with a moderate convexity or indication of a pair of such. The exoc- 
cipital portion (Pl. XII. 2) extends outward and slightly downward, expanding a 
little vertically, and thickening to form the paroccipital (4); this expanse is moderately 
concave transversely, convex vertically. The border of the paroccipital is thick and 
rugged: it is concave toward the otocrane (Pl. XII. fig. 1, and Pl. XIII. fig. 2, e), of 
which it forms the posterior half of the upper, and part of the posterior wall: it is 
divided below by a fissure (Pls. XII. & XIII. fig. 2,7) from the otocranial plate of 
the basioccipito-sphenoid (Pl. XII. fig. 1, and Pl. XIII. fig. 2,5’): this plate arches out- 
ward and downward, with a slight obliquity backward, and is overlapped anteriorly by 
the pterygoid (ib. 24’), which seems to form an anterior continuation thereof, converging 
towards its fellow: but the free border of the basisphenoidal otocranial plate (5’) is 
more obtuse and thicker than that of its pterygoid prolongation (24). A trace of the 
suture between the exoccipital (Pl. XII. fig. 1, 2) and squamosal (ib. 27) remains. ‘The 
ridge across the vertex (Pls. XII. & XIII. fig. 1, 7,11,3) is obtuse, but well marked : 
the proportions contributed by the superoccipital (3), parietal (7), and interparietal (if 
any) cannot be determined; and the frontal (11), as it ascends, contracting from the 
superorbital roof, is also blended with those constituents of the ridge'. The instructive 
harmonia between basi- (Pls. XIII. & XIV. fig. 1, 5) and presphenoid (ib. 9) remains. 
The alisphenoid (Pl. XIII. fig. 2,6), coalesced with the basisphenoid, where it is 
underlapped by the pterygoid ( 24’), is horizontal; it extends to the lower border of 
1 To afford a comparison with Physeter macrocephalus, I propose to append, in the present note, descrip- 
tions of the homologous cranial bones of a foetus of that species described, in my ‘ Catalogue of the Osteological 
Series in the Museum of the Royal College of Surgeons, 4to. 1853:—“ The elements of the occipital neural 
arch are unanchylosed. The lateral margins of the anterior half of the basioccipital are produced and bent 
obliquely downward. The exoccipitals are much produced and expanded laterally: they are deeply notched 
below. The superoccipital contributes the upper ends of both condyles: it is in the form of a vertical plate, 
conyex from side to side: a strong internal vertical crest is produced forwards: it is overlapped at its lower 
and lateral angles by the exoccipitals, anterior to which it reaches the alisphenoids, and is notched externally 
for the reception of the upper angle of the squamosal” (op. cit. p. 442). | 
F 2 
