1900.] ON THE BREEDING-HABITS OE WEST-AFRICAN FISHES. 835 



sardoiis (Studiati). There are slight differences between the 

 fossils of the two localities, but as they refer to secondary details 

 which cannot be well demonstrated without figures, I must post- 

 pone their discussion. 



Mr. J. S. Budgett, F.Z.8., read a paper entitled " The Breeding- 

 habits of some West-African Fishes, with an Account of the 

 External Features in the Development of Protopterus annectens, and 

 a Description of the Larva of Poh/pterus lapradii" in which a 

 history was given of a collecting-trip made during the previous 

 summer to the swamps of the Gambia Biver in search of the 

 eggs of Polypterus. 



The eggs of Polypterus were not discovered, though a very young 

 specimen was found measuring only one inch and a quarter in 

 length. In this small specimen the dermal bones were not de- 

 veloped, and the external gills were of very great size, the base of 

 the shaft being situated immediately behind the spiracle. The 

 dorsal finlets formed a continuous dorsal fin. 



While the eggs of Polypterus were being searched for, the under- 

 ground nests of Protopterus annectens were found in abundance, 

 and a complete series of eggs and larva? were preserved. 



The male Protopterus was found to live in the nest until the 

 larva? were fit to leave it. 



The nests of this fish were made in but a few inches of water ; 

 frequently the water round the mouth of the nest was dried up, 

 and then the parent was seen lashing the surface of the water in 

 the entrance to the nest with the end of its tail out of water. 

 The larva? were provided with four pairs of plumose external gills 

 and a ventral sucker as in Lepidosiren ; soon after hatching they 

 attached themselves to the sides of the nest by the sucker and 

 hung in a vertical position. 



The larvae hatched in eight days and left the nest as young 

 Protopteri in twenty days. 



Thee xternal features in their development were remarkably 

 like those of the South-American Lung-fish {Lepidosiren), differiug, 

 however, from the latter in several details, which possibly could be 

 traced to the presence in Lepidosiren of a larger amount of food- 

 yolk. 



The colour change at night-time, which is found to be so marked 

 in both members of the Dipneumona at a certain stage of their 

 life-history, was discussed, and was shown in Protopterus to be 

 associated with the nocturnal habits of the larva at this period. 



Xests were also found of Gymnarchus niloticus Cuv. These 

 Avere made in about three feet of water and floated on the surface. 

 The nests were two feet long and a foot wide, the wall of the nest 

 standing several inches out of water except at one end, where 

 it was two or three inches below the surface, and left an 

 entrance to the nest. Inside the nest the depth of water was 

 about six inches. 



The eggs measured lo mm. in diameter; the larva- hatched in 

 Proc. Zool. Soc— 1900, No. LV. 55 



