1572 sill. «. A. BOULENGEU ON 



toll otl"; tlio pieces somewhat resoniMod tlio Aving-cnses of a large 

 bootlo, lunng- somi-transpareut and of a eloar ovaui^o-coloiu-. 



.Dr. Francis W'Aun, F.Z.S., showed a numher of photogTa})hs 

 and diagraius illustrating a. method of observation of fishes, birds, 

 and mammals inider the Avater, the principle being that tho 

 subjects under eonsidei-ation Avere illinninated by natural light, 

 and the observer, being in a dark chamber in the water, was not 

 seen. The appearance of black-feathered birds was shown ; 

 these, by cai'i-ying down air-bubbles auiong the feathers, were 

 converted into rotlectors : and a Water- lien was shown bright red 

 and then green as it rellected the dill'erent surroundings in 

 which it hat! been placed. Otters and Seals were also shown as 

 seen nniler the water. Tlie demonstration was illustrated by 

 numerous slides and by tlie cinematograph. 



PAPERS. 



37, On a Collection of Fishes made by JMr. A. Blayney 

 roreival in British East Africa to tho East of Lako 

 Baringo. By G. A. Boulengeu, F.H.S., F.Z.S.* 



[Keooivcd Apvil 3, 1912 ; Read Mny 7, 1S)1'J.] 

 (Plates LXXVIII.-LXXX.t) 



Ijs.uex. 



SystiMuntic : Pago 



Jjahco percii'ali, sp. n 673 



Jiorhiis iu'iji/rot(enia,s\i.i) 674 



J?, m iiii IIS, sp. n O?'! 



A»iphiliiis o.vi/rhinus, syi, n 675 



Tihipiii inrciriiU, sp. n 676 



The collection here reported upon, presented to the British 

 ]\[useun\ by Mr. Blayney Percival, is of special importance as 

 coming from a tUstrict the fishes of which lunl not been collected 

 befoi-e, from a watei-shed of its own without any communication 

 with sea. The river called Eusso Nyiro, or Cuaso Xyiro, quito 

 distinct from the Southern Gua^so Nyiro in German East Africa, 

 takes its source to the east of Lake Baringo, separated from it 

 and from Lake Rudolf by hill-ranges 1000 to 1500 feet higher 

 (4000 to 5000 feet above sea-level) and is lost in the Loriau 



* Piihlislx-d liy permission of the Tnistocs of tho Hritisli ^Iiisi-uni. 

 t For oxpLiiiatioii of tlio I'lates see p. 676. 



