400 ME. a. A. BOULENGEE ON A COLLECTION OE FISHES 



resulted from the Expedition, Mr. Woosnara is to be congratulated on having supplied 

 a desideratum of long standing in African Ichthyology, which has made such rapid 

 proo-ress during the last few years. I beg to express to him my grateful thanks for all 

 he has done. 



The specimens in the collection number 87, referable to 25 species *. They are now 

 preserved in the British Museum. 



Mr. Woosnam's report is here appended, and I may add that the notes and coloured 

 sketches he has made on the fishes in the fresh condition have been useful in drawing 

 up descriptions of the new or imperfectly known species. 



" With regard to the present small collection from Ngamiland, although the fish 

 are labelled ' Lake Ngami ' for the convenience of reference to maps, they come 

 in reality from the Okovango river and vast extent of marshes (of which Lake Ngami 

 is a part) into which the river opens out before it continues its way as a single great 

 river known as the Botletle or Zouga. 



" The physical geography of Ngamiland and the Kalahari Desert may shortly be said 

 to consist of a great shallow basin or valley surrounded by higher land. There is only 

 one outlet to the sea towards the Orange river. The lowest part of the whole central 

 and North Kalahari basin is the Great Makarikari Salt Pan, and I am inclined to 

 think that there is a low, broad ridge running across the Kalahari somewhere about 

 23° South, and forming a low watershed between the Okovango and Nolopo Nosop 

 river-systems ; it was part of this ridge which we noticed north of Lehutitu. 



" Travelling from Lehutitu to Okwa one passes for three or four days by ox-wagon 

 over a strip of country which rises some 400 feet above that south of Lehutitu, and a 

 thousand feet above Lake Ngami ; this elevation would not be detected unless altitudes 

 were taken daily, as the rise is very gradual and undulating, but the condition of 

 the grass on this higher country was most noticeable. Here there had evidently been 

 more rain, and that more recently than below, for there were quantities of young green 

 grass twelve inches high in June, while the surrounding country was scorched and 

 yellow, showing that more moisture and local rains had been attracted by this rising 

 ground. Also, as soon as the descent from this elevation to the Lake was begun there 

 was a marked change in the vegetation, and many semi-tropical trees, plentiful in the 

 lake district, began to appear, marking, I believe, the Ngamiland side of this low 

 watershed. Again, on the east side of the desert there is a similar phenomenon, but 

 more sharply accentuated, the fall from Palapye level to the nearest point of the 

 Botletle river being rather more than 2000 feet. This was noticed by Livingstone 

 in 1849 (see Livingstone's ' Missionary Travels in South Africa,' chapter 3, p. 66). 



* Three of the new species, belonging to the family SilmridEe, have been described and figured in the 

 recently published volume of the ' Briti.sh Museum Catalogue of African Fresh-wat^r Fishes ' (1911), and the 

 figures are reproduced here by permission of the Trustees 



