408 A new Genus for " Akodon " teguina. 



each other that they would be supposed to belong to a single 

 species were the skulls and teeth not examined. 



Of the genus Phyllotis the new species is perhaps most 

 allied to Ph. andiiun, but has much shorter ears aud tail, 

 apart from its darker coloration. 



A new Genus for " Hesperomys ^^ or " Akodou " teguina, 

 Alst.^ and its Allies. 



On going through the vole-like vesper-mice of the Neo- 

 tropical region to see which should be assigned to Ahodon 

 and which to Zygodontomys (no easy task, for the two are 

 unexpectedly close to each other), I have found that, with 

 the uncertain exception of A. urichi and venezuelensis, no 

 species rightly assignable to Akodon are yet known to occur 

 north of a line drawn from the S.W. corner of Colombia to 

 the eastern angle of Brazil north of Pernambuco. ^'Akodon " 

 hogotensis was some time ago separated as a Microxus^ and I 

 now find that ^''A." meridensis, Allen, and "xl." fuscinus, 

 Thos., of Marajo, are both members of Zycjodontomysy which 

 may be distinguished from Akodon by its rather less hj^pso- 

 dont and less complicated molars and its more distinctly 

 angular or beaded supraorbital edges ; the front margin of m^, 

 in young specimens^ is distinctly notched in Akodon, entire in 

 Zygodontomys, but unfortunately adult specimens do not show 

 this diagnostic mark. 



One small group of species, however, from far north of the 

 above-defined line is clearly not referable either to Zygo- 

 dontomys or Akodon, differing very definitely from both by 

 the structure of the teeth. This consists of the '"'' Hesperomys " 

 teguina oi Alston, more recently known as ^^ Akodon" teguina, 

 and the species or subspecies closely related to it described by 

 Bangs and Allen. I would propose to form for it the 

 following : — 



SCOTINOMYS, gen. nov. 



Most nearly related to Akodon, but the teeth of different 

 structure and the zygomatic plate almost without any pro- 

 jection forwards. 



Molars exceedingly narrow, laterally compressed, the 

 notches and re-entrant angles, both on upper and lateral 

 surfaces, much reduced in depth, so that the upper profile in 

 little-worn teeth is almost straight, without deep angles 

 between the laminre, and similarly tiie outlines of the teeth 



