PEOFESSOR OWEN ON INDIAN CETACEA. 35 



(Pis. XII., XIII., & XIV. fig. 2, 1 ) beneath the foramen magnum (ib. o) 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 

 (PI. XII. fig. 2, 2') are more sessile than in Pkoccena brevirostris, being raised only 

 by a linear border from the contiguous bone, except at thek 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, mth the larger end upward and not 

 notched : the aspect of the plane of the aperture is backward and a little upward : in 

 Physeter macrocephalus (PI. XIV. fig. 2, o) 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 (PI. 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 (PI. XII. fig. 1, and PI. 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 (Pis. XII. «& XIII. fig. 2,1) fi-om the otocranial plate of 

 the basioccipito-sphenoid (PL XII. fig. 1, and PI. 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 fi'ee border of the basisphenoidal otocranial plate ( 5' ) is 

 more obtuse and thicker than that of its pterygoid jDrolongation (24). A trace of the 

 suture between the exoccipital (PI. XII. fig. 1, 2) and squamosal (ib. 27) remains. The 

 ridge across the vertex (Pis. 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 fi-om the 

 superorbital roof, is also blended with those constituents of the ridge'. The instructive 

 harmonia between basi- (Pis. 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 



' 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 Ostcological 

 Series in the Museum of the Eoyal 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, 

 convex 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. cif. p. 442). 



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