PEOE. E. EAT LANKESTEE ON LEPIDOSIEEN AND PEOTOPTEEUS. 13 



absence from his description of any distinctive characters, no one will be found to 

 agree with him. 



The view taken as to the Paraguayan Lepidosiren being distinct from that of the 

 Amazons will no doubt depend, to some extent, on the conclusion which is accepted 

 as to the existence of a single species of Protopterus in the African continent. If 

 we agree with Dr. Giinther that Peters's Protopterus amphibius from the Zambesi 

 (Quillemane) is not really distinct from the Protopterus annectens, Owen, of the 

 western water-shed of Africa (Gambia), then it will seem not unlikely that a single 

 species of Lepidosiren may similarly inhabit two distinct river-systems in South 

 America 1 . 



From an examination which I have made of specimens of Protopterus in the British 

 Museum and elsewhere, I cannot regard the question of the species of African 

 Protopteri as finally settled, and would venture to point out that it is very desirable 

 that large and well-preserved specimens should be secured, by those who may have 

 the opportunity, from each of the different river-systems of Africa and deposited in 

 European collections for study. It seems that we must either admit that a very 

 marked range of variation is exhibited (as is a priori likely enough) in specimens of 

 one species of both Protopterus and Lepidosiren, or that more than one species has to 

 be recognized in each genus. 



On the whole, I think it will be best to assume for the present that Bohls's Paraguay 

 Lepidosiren 2 is identical with the L. paradocca of Fitzinger and Natterer, and I now 



1 It appears that Professor Peters refers some of the specimens from the Zamhesi and also those from the 

 Nile and from the Tanganyika district to the species P. annectens of Owen, and that his P. amphibius is repre- 

 sented only by certain specimens brought by him from the district of the delta of the Zambesi (Quillimane), 

 and preserved in the Berlin Museum. P. amphibius is stated to possess only thirty pairs of ribs instead of 

 thirty-five (P. annectens), and as its specially distinctive character is given not merely that a fin-membrane 

 (' Elossensaum ') is present on one border of both pectoral and pelvic limbs (instead of on the pectorals only, as 

 in P. annectens), but that the membrane in both limbs is supported by minute cartilaginous rods, which are 

 wanting in P. annectens. (See Schneider, ' Zoologische Beitrage,' vol. ii. 1890, p. 97). 



The determination of the presence or absence of the minute fringing cartilages of the fins requires the use of 

 the microscope. I have examined specimens from the Zambesi (in the British Museum) with a fin-membrane 

 well developed on the hinder limbs, but was not able to apply the microscope. As to how far these characters 

 are really indicative of specific separation is still doubtful, and can be cleared up only by minute examination of 

 large series of specimens, which it is to be hoped will soon be forthcoming now that our communication with 

 Equatorial Africa is so greatly improved and extended. 



2 Prof. Ehlers, in an interesting communication to the Royal Society of Sciences of Gottingen (' Nachrichten,' 

 1894, p. 84), gives reasons for considering that Dr. Bohls's collection of Lepidosiren from Paraguay consists 

 •of two species — one which he considers identical with Natterer's L. paradoxa, and a second which he distin- 

 guishes as L. articulata, n. sp. Prof. Ehlers had the opportunity of looking over thirty-two specimens from 

 Paraguay, of which he considers that twenty-seven belong to his new species, whilst five are to be referred to 

 L. paradoxa of Fitzinger. 



The characters adduced by Prof. Ehlers for separating these two species appear to me to be insufficient 



