DYACOPTERUS. 



653 



one specimen, in lower rov,- those of C^^wpterus). Fur of sindo 

 species known unusually short anrl cU^.U .a,,J...a ':. ""^'? 

 above. 



Illy short and closely adpressed, tibia naked 



4/^;ii^,Vs.--The single species of this genus "r,mnr,u,',.." 



t:z iT '' '''"^/; ^''''^ p'-^^ irf Sv^rt ^h tr: 



nc uded two species, 2h. nir,rescens (type of genus) and Th spadk^s 

 Eut whatever may bo the real affini ies oi spadiceus it is n m- t' 

 and important characters so different from J^.^'l^^^^ 

 be admitted into the same genus. In Tljpterus, if restrict to 

 the species n.^.,5..n., the rostrum is typical Cynopterine inDuarn 

 pterus peculiar y modi^fied (deep, premaxilla3 brlid om^kl^S' 

 and produced forward n fn.nt of canines, nasals hro^ad ned fa 

 Ihoopterus the postorbital foramina are absent, in DuacolteZ 

 present; in Thoopterx^ the inner ridge of the Inr-e i r^^nl ? I 

 molars is extremely low or even perfectly oWete: i 1"^^^^^^^^^^^ 

 Me 1-developedoreven stronger than usual; in ^.o »^.. J Kt"r 

 and inner cusps of P3 are completely fused, in ^^c^^.^^^ separl 

 both genera possess surface cusps in p, and m„ but thele cups' 

 d ffer no iceably in position, being in V«co;^^..«y situated else '^ 

 and partly confluent with, the inner ridge, in Thoovtern. tnt! ' 

 Wy central and freely projecting ; ^n tZ^T^LV^:: 

 in Z)„,,.„. absent or at least deciduous (only one spec men t 

 known); in Ihoopterrjs the tail is reduced to a minute Si" i 

 Byacoptencs unmodified Cynopterine; in Thoopten,s the Jur s 

 unusually long and the tibia densely furred abo've, in dZcXZ 

 /W /' '^'^'^l^y l^^'^ and adpressed and the tibia nakedTbovT 

 Dyacopterus might be roughly described as a ^^ CpwptenJT.k 

 the pecul.ar cranial characters referred to above, but with le len 

 ition essential y unmodified, except for the l^ng groved upper" 

 canmes without secondary cusp (compare grooved u^per canines n 

 Ptenoch,rus, which undoubtedly is very closely allied ^oCvX,n"> 

 with ungrooved eanines), the broader eheek-teeth (compare bo d 

 cmng ol cheek-teeth in P..„o.;-»-«,s and the '' i\7..^Z^«s "section of 

 Cynopterus), and absence or deciduousness of p\ On the o bpr 

 hand, the remarkably email size of the postorbital foramina may 

 indicate leanings toward 7?«?.o»v.Y..,X Chirona., ThooZZ Z 

 lenthetor, in all of which these foramina are entirely ibent the 

 1,1 r^ r ^.' palate may point toward Thnopten,s and Penket^r 

 while the Bhght reduction of m' and m, recalls the much ronge; 

 reduction of the same teeth in Daliouycta-is and r7»V." . Thfre 



