936 AN EXPEDITION TO THE GAMBIA. [NoV. 28, 



In the open plains, where clumps of tall dead grass were shaded 

 by a few trees, one might generally count on starting a Ivonko- 

 tong (Cohus kob), some Gazelles, or a Harnessed Antelope. The 

 smaller solitary Antelopes were usually found in pairs. Enquiries 

 were instituted everywhere as to the existence in this region of a 

 Zebra, but I could hear nothing of it. 



The horns either collected by me or from the natives included 

 those of 9 species : — Buhalis major, Damaliscus korrigum, Cohus 

 unctuosus, Cobiis Jcob, Cervicapra redunca, Bijjpotragus equinus, 

 Tragelaplms scriptus, a second species of Tragelaphus not yet 

 determined, and Oreas derhianus. 



Buffaloes were said to be common on Deer Island, but they were 

 not seen by me, though horns of two forms were obtained from 

 natives. 



On the way back, a cutter was taken from Fatoteuda to 

 M'Carthy's Island, and after a few days spent at the Government 

 House attending to my collections, and my living fishes and reptiles, 

 I paid a final visit to Nianimaru. During this time, being the 

 latter part of May, the rainy season began and the swampy places 

 became filled with water. The Frogs began to spawn, and several 

 sei-ies of stages in development of the different forms were pre- 

 served. 



Here I first obtained free swimming ProtojJterus with ripe ovaries : 

 examples of 8 Frogs, 3 Ohelonians, 5 Lacertilia, and 9 Ophidia, 

 including a TypJdops, were also collected about this time. 



Eetiu-ning to M'Carthy's Island, it was found that a number of 

 Polgpterus lapradii which had been kept in a pool connected witb 

 the river in the hope of getting them to spawn had been set free 

 by the rising river. However, during the latter part of June and 

 July a large number of Foli/ptcms of both species were obtained, 

 the females of which were crowded with ripe eggs. Artificial 

 fertilization was tried with these, without success. Many were 

 kept in confinement, and some, of which a pair are now exhibited, 

 were successfully brought alive to England. 



About the 10th of July, in the same swamp where these fishes 

 were obtained, several nests of eggs were found. These eggs coin- 

 cided in measurement exactly with the ovarian eggs of Pulypierus. 

 The young larvae possessed cement-organs on the front of the head 

 so characteristic of Ganoid larvae ; and other characters led me 

 to assume that they were the young of Pohjpterus. None were 

 reared beyond the larval state, and their identity could not well 

 be established. However, having stayed on the Gambia three 

 months longer than I had intended, and having a number of 

 healthy Poh/pteri full of spawn, I decided to return home. 



Just a day or so before leaving M'Carthy's Island I obtained eggs 

 of Protopterus. These were watched through the early stages of 

 segmentation, but the young could not be reared. On July 25 

 I left M'Carthy's Island and returned to England. 



Several Polypjieri and Protopteri, 12 young Crocoddiis cnta- 



