180 Prof. Eschricht on the Gangetic Dolphin. 



reduced only to one-fourth* its original size ; and in other respects 

 I can refer to Mr. Gray's instructive figure (Illustr. p. 353). An- 

 teriorly the lower teeth are seen to embrace as it were the upper 

 jaw, leaving a deep furrow on the outer side of the opposed gum. 

 Midway in the jaws, the apices of the teeth meet the correspond- 

 ing gums, close to the outside of their own teeth, where they 

 leave a small round impression ; quite behind, the lower teeth 

 project more than 1'" from the outside of the upper gums. 



The os hyoideum does not differ from that in other whales. 

 It consists namely, as is usual, of two arched cartilages; the 

 posterior having three points of ossification — one in the middle 

 (corpus ossis hyoidei), and one in each side-branch (cornua 

 majora) ; the anterior having only one point of ossification in each 

 side-branch, while the middle part, without ossifying, turns back- 

 wards on each side, towards the ossified middle of the posterior 

 arch, on which it inserts itself (cornua minora) . The ossification 

 had not extended further in the posterior arch, than to leave a 

 plate of cartilage, of the thickness of about 2"', between the middle 

 part and the ossified part of the cornua majora, which were car- 

 tilaginous outside about one-fifth their length. The side parts 

 of the anterior arch are cartilaginous inwardly about half their 

 length, and outwardly towards their insertion on the occipital 

 bone to about one-fourth of that extent. 



Cuvier counted eleven pectoral vertebras, assuming that twelve 

 might possibly be the proper number. In M. Reinhardt's ske- 

 leton there are, however, only eleven pairs of ribs, and it is ma- 

 nifest that there never were more; because the 11th pair is at- 

 tached both to the terminal margin of the transverse process of 

 the 11th vertebra (PI. V. fig. 2), and by the margin of its ver- 

 tebral extremity, to the obliquely truncated transversal process of 

 the next following vertebra, so that here, at least, no other rib 

 could have had insertion. But Cuvier counted altogether only 46 

 vertebras in his specimen, namely 7 cervical, 11 pectoral, and be- 

 yond these only 28 more. M. Reinhardt's skeleton counts 51 

 vertebrae, namely 7 cervical, 11 pectoral, 8 lumbar and 25 caudal. 

 This great difference (between 46 and 51) cannot be taken as 

 an individual one ; and many zoologists would probably feel 

 disposed to found upon it a specific distinction. But this lat- 

 ter could only be warranted, in case it were found that Cuvier's 

 specimen too was perfectly complete; that the point of the 

 tail wanted not even the last vertebra (which in M. Reinhardt's 

 is a minute bony nucleus scarcely 2'" in diameter), and the 

 other vertebras were united by means of their natural liga- 



* This refers to the figure given by the author : we have been com- 

 pelled, in order to suit the size of the ' Annals,' further to reduce all the 

 figures ^ths. — Ed. 



