10 



POLYPTERID.E. 



across the back, the first on the nape; on the sides these bands are directed backwards, 

 or break up into branches or detached spots ; lips and fins with blackish spots, these 

 usually forming transverse lines on the pectorals and ventrals, and oblique wavy lines 

 or vermiculations on the dorsal ; belly creamy white, sometimes slightly tinged with 

 orange ; iris bronzy. 



The single known specimen with external gills, obtained by Dr. Ansorge at Agberi, 

 Niger Delta, measures 180 millimetres ; the external gill 50. The markings do not 

 differ from those of the adult. 



Grows to a length of 710 millimetres. 



Measurements (in millimetres) and numbers of dorsal spines and scales. 



Total length (without caudal fin) . . . 



Greatest depth of body 



Length of head 



Width of head (at temples) 



Length of snout 



Diameter of eye 



Interocular width 



Length of first dorsal spine .... ... 



,, last dorsal spine 



Number of dorsal spines 



,, scales in a longitudinal series . 



„ ,, round body 



,, „ from occiput to first 

 dorsal spine 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 

 355 



9. 

 330 



10. 

 245 



11. 



225 



12. 

 145 



630 



620 



610 



570 



520 



450 



440 



73 



84 



70 



67 



67 



52 



55 



42 



41 



35 



25 



20 



130 



125 



122 



105 



110 



90 



88 



71 



72 



55 



51 



37 



85 



80 



80 



67 



70 



55 



53 



43 



45 



35 



31 



20 



19 



20 



18 



18 



19 



17 



13 



13 



13 



11 



10 



6 



9 



9 



9 



9 



9 



8 



8 



7 



7 



6 



6 



4 



33 



34 



35 



32 



27 



24 



23 



18 



18 



13 



13 



9 



31 



25 



31 



26 



26 



20 



17 



17 



16 



11 



11 



7 



43 



38 



41 



46 



44 



35 



34 



31 



25 



22 



18 



16 



12 



12 



12 



13 



13 



14 



13 



12 



13 



13 



12 



11 



56 



56 



55 



58 



57 



55 



56 



57 



56 



54 



56 



55 



44 



44 



42 



44 



44 



42 



44 



42 



46 



44 



42 



46 



13 



13 



15 



12 



12 



13 



11 



13 



13 



13 



12 



12 



1. 10. Sbederah, "White Nile.— -Loat. 



2. Fasboda. — Loat. 



3. Kawa, White Nile.— Loat. 



4. Goz abu Gumah, White Nile. — Loat. 



5. Mouth of L. No.— Loat. 



6. Gondokoro. — Loat. 



7. Niger. 



8. L. Chad.-— Gosling. 



9. Khartum. — Petherick. 



11. Goz Shebesha, White Nile. — Loat. 



12. Agberi, Niger. — Ansorge. 



I have examined twenty specimens of this species; of these, one has 11 spines in 

 the dorsal fin, eleven have 12, six have 13, one has 14, whilst one (from Goz abu 



