166 TELEOSTEI. P1IYSOSTOMI. 



the occipital process nearly as long as wide at its base, notched 

 anteriorly to receive the basal bone of the dorsal fin, which is nearly 

 as long as the occipital process. Upper jaw the longer ; width of 

 the mouth nearly equal to half the length of the head. Cubito- 

 humeral process more pointed in young than in adult specimens 

 and about three fourths the length of the head. Barbels the nasal 

 short ; the maxillary nearly reaching the end of the head, and the 

 mandibular almost as far. Teeth villiform in the upper jaw, also 

 in the anterior portion of the mandible, and in an outer row along 

 either ramus, while internally are two or three rows of rounded 

 teeth, the posterior of which are the largest ; two elliptical patches 

 of rounded teeth on the palate, which are wide asunder along the 

 median line but coalesce anteriorly. Fins dorsal spine very 

 strong, and slightly serrated posteriorly in its upper portion ; its 

 length varies, being shortest in the immature, it is generally as 

 long as the head (except in the young) or even one third longer in 

 adults, especially in those from the Indus ; base of adipose fin 

 half or two thirds that of the rayed fin, or of the interspace between 

 the two fins. Pectoral spine (except in the very young) somewhat 

 shorter than that of the dorsal and denticulated on both edges. 

 Ventrals arising just behind the vertical from the last dorsal ray. 



Fig. 66. Rita buchanani. 



Anal one half higher than its base is long. Colour lurid green, 

 lightest below, and the hind edge of the dorsal sometimes blackish. 

 Air-bladder with a thick outer covering, and of an almost quad- 

 rangular form, whilst posteriorly it is continued into two horn-like 

 prolongations nearly as long as the abdominal cavity, the right one 

 generally passing over to the left side and curving across the com- 

 mencement of its fellow, whereas the left one passes backwards, 

 and is then as a rule recurved on itself. On the inferior wall 

 being removed a longitudinal median partition is seen in the 

 posterior half, dividing it into two lateral chambers which anteriorly 

 communicate together, while posteriorly they are continued down 

 the two horn-like processes. 



Hob. Indus and affluent rivers, Jumna and Ganges, also the 

 Irrawaddy ; attaining at least 4 feet in length. This fish is 

 esteemed as food by the natives, but is a very foul feeder. 



