390 Fiof. E.-L. Trouessart ow Neotetracus sinensis. 



verse crest ; the second has only four tubercles, 2 and 2; tlie 

 third is smaller, but similar to the second, slightly narrowed 

 behind. 



All these teeth, in both jaws, have their points intact, 

 sharp (and not worn as in Erinaceiis). 



Affinities and Differences. — According to the figures 

 published by M. W. Lyon of the unique specimen of Podo- 

 gymnura truei, ISeotetracus resembles it in its external form, 

 notably in its w'ell-developed tail, but it differs from it 

 very decidedly by the dentition. The skull of Neotetracus 

 resembles, moreover, that of Hylomys, but the canine is 

 still more reduced than in that genus ; in Neotetracus the 

 canine and the premolars want the i:)Osterior spur which 

 is very prominent in Hylomys. The lower jaw presents 

 still more striking differences : in Hylomys the lower 

 incisors decrease very gradually from the first to the third, 

 keeping their spatulate shape ; in Neotetracus the large 

 anterior incisor is followed by two very small atrophied teeth, 

 so that between the large anterior incisor and the large 

 third premolar there are five small subequal functionless 

 teeth. Seen in profile the jaws are still more dis- 

 similar : in Hylomys the anterior part of the ramus 

 is bent downwards in spade form ; in Neotetracus this 

 anterior part, more constricted, is, on the contrary, turned 

 upwards. 



By its incompletely ossified palate, as by its reduced 

 canines, Neoteti-acus approaches Erinaceus, but this lacunar 

 character of the palate has probably not the value which 

 has been attributed to it, as all intermediate conditions are 

 found. By its small size (it is the smallest living species 

 of the family), its slender jaw, and the form of its 

 inferior molars the new type approaches Tetracus nanus, 

 Aymard *, a fossil species from the Tertiary of France, 

 known only from an incomplete fragment, and of which the 

 fore dental formula is unknown. 



To sum up, Neotetracus joins the Gymnurinas to the 

 Erinacein^e, and it will perhaps be necessary to unite the two 

 subfamilies into one, or to distinguish them solely by the 

 nature of their pelage. 



Neotetracus sinensis, sp. n. 



Form recalling those of Macroscelides and Podogymnura. 

 Head conical, elongate, with the snout projecting beyond the 



* Avmard, Ann. Soc. du Puy, 1848, p. 244; 1849, p. 110: Filliol, 

 Ann. be. Geol. xii. 1882, p. 8, ij1. vi.figs. 7-9. 



