236 Mr Budgett, Observations on Polypterus and Protopterus. 



Observations on Polypterus and Protopterus. By Mr J. S. 

 Budgett. 



[Received 9 December, 1899.] 



The following observations on the Crossopterygian Polypterus 

 and the Dipnoan Protopterus were made on the river Gambia 

 1898—99. 



The Gambia flows due west, and lying between the 13th and 

 14th parallels of north latitude is tidal throughout its navigable 

 waters, that is, to a distance of 260 miles from the sea. 



a. Two species of Polypterus were obtained, Polypterus 

 lapradii, Steind. and Polypterus senegalus, Steind. The former 

 was taken 31 inches in length. The latter never more than 

 12-| inches. 



The two species are perfectly distinct. P. lapradii has not 

 fewer than 13 free dorsal finlets. The head is flattened dorso- 

 ventrally and elongated. The body surface is variegated with 

 dark greyish green markings on a yellow ground, taking the form 

 of spots on the sides of the head and on the pectoral fin, but of 

 blotches arranged in rows on the sides of the body elsewhere. 

 The external gill is retained on the operculum until the young 

 fish is 9 or 10 inches in length. 



P. senegalus, on the other hand, has not more than 9 free 

 dorsal finlets, the first arising on the 1 9th row of scales, whereas 

 in P. lapradii the first arises on the 13th row. The head is 

 shorter, round and deeper, while the body surface is a uniform 

 dark green above and bright yellow below. The external gill in 

 this species is lost by the time the young fish is 3| inches in 

 length. 



In both species there is a marked difference between the 

 male and female. The anal fin in the male is broad and fleshy 

 with deep folds ; in the female it is narrow, thin and pointed. 



In the Gambia the rainy season begins in June and continues 

 until October. In the early part of June Polypterus begins to 

 migrate from the river to the flooded, low-lying plains ; it spawns 

 during August and September, returning to the river in October 

 and November. 



In the river Polypterus is one of the most difficult fish to 

 catch. P. lapradii however was caught from time to time in the 



