30 



known to occur in various rivers opening into the Bight of Biafra, 

 which have hitherto been referred to the same species, partly because 

 no specimens had hitherto been critically examined, and partly because 

 it seemed unlikely that two species of a genus so unprolific, even in 

 individuals, should exist in localities so very near to each other. All 

 probability from previous knowledge, or in the absence of more pre- 

 cise or more extended information, merely justified a belief in the 

 existence of two species, one inhabiting the New World, the other 

 peculiar to some tropical portions of the Old World. 



The differences between M. anstralis and 31. Senegalensis are 

 quite evident. The former seems to grow to a greater size, and the 

 shape of the skull at once distinguishes it, being altogether larger, 

 with a more lengthened nasal opening, and more elongated inter- 

 maxillary bones, giving it a large mouth. The lower jaw, also, is 

 less massive and angular, and its inferior margin less curved. It 

 would seem to approach more to the fragmentary extinct forms de- 

 scribed by Cuvier in his ' Ossemens Fossiles.' In M. Senegalensis 

 again the skull is more compact, the snout shorter, the lower jaw 

 more angular with its lower border more curved, and the zygomatic 

 process of the temporal is less elevated. 



In 1851, while Dr. Barth was journeying towards the country of 

 Adamawa in Central Africa, he heard from the natives, accounts of 

 an animal said to frequent the rivers and marshes named by them 

 Ayii (erroneously written Ajuh). He heard of the same animal, 

 under the same name, also up the river Kwdra or Niger below Tim- 

 buktu, and he believes that it also exists in the river Shari, which 

 runs into the marshy Lake Tsad. Dr. Barth not having been able 

 to satisfy himself about this creature, directed Dr. Vogel's attention 

 to it, and the latter gentleman fortunately met with a specimen in 

 September 1855 in the upper part of the Binue or Tsadda. An ac- 

 count of this Ayii having been sent by him to England, and read at 

 the British Association Meeting at Cheltenham, Prof. Owen thought 

 that it presented sufficient peculiarities to distinguish it as a species, 

 which he indicated as M . Vogelii ; but his remarks partly applied to 

 a Manatus skull, which was exhibited at the time, and which by 

 some misconception persons present had been led to consider as be- 

 longing to the very individual described by Vogel. 



During the months of September and October 1854 I ascended 

 the same river ; but though this was the period when they ought to 

 have been most abundant, yet I neither saw nor heard of any such 

 animal ; and though I always carefully examined the hunting relics in 

 the various villages, yet I never met with its remains. From this I 

 am led to confirm Dr. Vogel's statement, that it is a rare and scarce 

 creature. But on the 13th July previous, just after I had entered 

 the mouth of the Kwora and Niger from the sea, I had spent the 

 day in examining some of the interminable dreary creeks, which are 

 there so apt to perplex the voyager. While returning in the after- 

 noon I saw under some palms and mangroves a collection of miserable 

 huts, hardly entitled to the appellation of a village, towards which I 

 pulled and presently landed. The inhabitants in great alarm all fled 



