the Species o/'Polypterus. 417 



Synopsis of the Species. 



I. Mandible projecting very slightly beyond the snout ; 



subopercle larger than the eye ; dorsal with 12 to 

 18 spines ; pectoral extending as far as first dorsal 

 spine or beyond ; 42-52 scales round middle of 

 body. 



A. (>0 to 68 scales along the body. 



15 to 18 dorsal spines ; head If to 2 as long as broad, 

 5 to5§ times in total length; interorbital region slightly 

 convex 1. /'. bichir. 



14 dorsal spines, rarely 13 or 15 ; head 2 to 2} as long 

 as broad, 4£ to 5 times in total length ; interorbital 

 region flat 2. P. Lapradii. 



B. 54 to 57 scales along the body ; head H to If as 



long as broad. 



13 or 14 dorsal spines ; head 4 to 4§ times in total 

 length ; an azygos shield between the nasals 3. P. co?i;/icus. 



12 or 13 dorsal spines : head 4£ to 5| times in total 

 length ; all the head-shields paired 4. P. Endlicheri. 



II. Snout projecting very slightly beyond the man- 



dible ; subopercle smaller than the eye ; dorsal 

 with 5 to 10 spines ; pectoral not reaching first 

 dorsal spine ; head 1§ to 2 as long as broad. 



9 dorsal spines ; 57 scales along the body, 44 round 

 the middle ; head 4^ times in total length 5. P. Weeksii. 



8 to 10 dorsal spines ; 55 to 59 scales along the 

 body, 36 to 38 round, the middle ; head 5f to 7 times 

 in total length 6. P. senegalus. 



5 to 8 dorsal spines ; 52 to 55 scales along the body ; 

 head 4| to 5§ times in total length 7. P. palmas. 



1. Pulypterus bichir , Geoffr. 



Head If to 2 as long as broad, 5 to 5| times in total 

 length ; interorbital region slightly convex ; all the head- 

 shields paired ; subopercle larger than the eye ; mandible 

 projecting very slightly beyond the snout. Dorsal spines 

 15-18 ; anterior 5 or 6 times as long as broad, overlapping 

 when folded. Pectoral reaching first dorsal spine or a little 

 beyond. 60-68 scales along the body, 46-50 round the middle. 

 Body with more or less distinct dark stripes and cross-bars ; 

 fins spotted or streaked. 



Total length 570 millim. 



Nile, Senegal, Gambia. 



1. Cairo XVII 



2. Nile 



3- „ 



4. Senegal 



5. Gambia 



6. W. Africa 



"• „ 



8. ? XVII 



