560 



CETACEA. 



Fig. 25. 



The transverse processes of the dorsal region gradually increase in length and 



breadth to the fourth, 

 the transverse process 

 of the first dorsal being 

 shorter than that of 

 the last cervical, and 

 all these processes, as 

 usual, are much for- 

 wardly directed. A sud- 

 den change, however, is 

 inaugurated in the fifth 

 dorsal, in which the pro- 

 cess is outwardly direct- 

 ;}) ed and considerably 



longer than in the fourth 



vertebra and much ex- 

 Ninth dorsal vertebrae seen from behind, reduced nearly ^th natural size. , , , . , „ 



panded at its free end. 

 Erom tliis point, the processes increase in length to the tenth dorsal which is 

 the last, as there are only ten ribs, and they are gradually pushed somewhat back- 

 wards, and all are considerably contracted at their bases and middles. In the first 

 lumbar, they markedly diminish in length and assume an entirely different character, 

 being short and but little expanded at their ends. As they are traced backwards in 

 the lumbar region, the diminution in their length is very gradual, and one of the chief 

 features is the marked increase in their breadth, associated with a basal contraction. 

 In the last lumbar, there is another change introduced as the process begins to 

 decrease in size by a lessening of the dimensions of its anterior border which becomes 

 bevelled off, and by a rapid reduction in the length of the process ; so that in the seventh 

 caudal, it becomes reduced to a lateral ridge. In the third caudal, it is perforated. 



One chevron bone was forwarded to me along with the other bones. It is 

 halbert-shaped and has a vertical depth of 7 '75 inches, and a maximum breadth 

 at its expanded portion of 6*40 inches. 



Of the ribs, a fragment of the fijst rib of the left side was saved, and the entire 

 sixth rib of the same side (fig. 26) . The former is a portion of the shaft and of the 



Fig. 26. 



Sixth rib of the Sittang Whale, reduced ith natural size. 



