SYNODONTIS. 



367 



much longer than broad, distinctly keeled, sharply pointed, extending as far a$, and 

 usually beyond, the occipito-nuchal process. Skin smooth, without villosities. Dorsal 

 fin with I 7 rays, the spine strong, straight or feebly curved, smooth in front, serrated 

 behind, three-fourths to once the length of the head, with a short terminal filament. 

 Adipose dorsal fin twice and two-thirds to three times as long as deep, once and 

 two-thirds to twice as long as its distance from the rayed dorsal. Anal fin rounded, 

 with 12 or 13 rays, 8 or 9 of which are branched. Pectoral spine three-fourths to once 

 the length of the head, feebly serrated on the outer edge, strongly (6 to 17 serrse) on the 

 inner edge, reaching or not the root of the ventral fin. Ventral fin rounded, reaching 

 the anal or not quite so far. Caudal fin deeply forked, upper lobe slightly the longer. 

 Caudal peduncle as long as deep or a little longer. 



Measurements (in millimetres). 



1. 



2. 



3. 



4. 



5. 



6. 



150 



130 



125 



115 



75 



48 



46 



42 



35 



32 



20 



15 



46 



42 



36 



35 



23 



16 



36 



35 



31 



30 



20 



11 



18 



16 



14 



14 



9 



6 



9 



8 



7 



8 



4 



4 



22 



20 



16 



16 



10 



6 



13 



12 



11 



10 



6 



4 



53 



50 



37 



53 



22 



16 



30 



25 



22 



27 



11 



9 



15 



12 



12 



14 



6 



5 



39 



38 



32 



35 



24 



15 



23 



20 



19 



18 



10 



8 



38 



30 



27 



26 



17 



11 



13 



10 



9 



8 



5 



4 



44 



42 



32 



34 



20 



14 



Total length (without caudal fin) 



Greatest depth 



Length of head 



Width of head 



Length of snout , 



Diameter of eye 



Interorbital width 



Width of mouth 



Maxillary barbel 



Outer mandibular barbel 



Inner mandibular barbel 



Length of dorsal spine 



Basal length of dorsal fin , 



„ „ adipose fin .... 

 Greatest depth of adipose fin . . , 

 Length of pectoral spine , 



1, 2. Tonga. — Loat. 



3. Gambia. — Budgett. 



4. Wadelai.— Budgett. 



5. Kaedi, Senegal. — Delhez. 



6. Polkom, Baro B. — Zaphiro. 



