1807] 



DR. J. E. GRAY ON AUSTRALASIAN RATS. 



599 



and two pectoral teats well developed, and a young female in the 

 Museum Collection. 



ECHIOTHRIX. 



Head elongate. Nose elongate, compressed, concave on the sides ; 

 apex produced, acute ; underside with short close bristles and a small 

 central groove ; nostrils apical, lateral. Fur soft, crisp, with abundance 

 of bristles, flat and channelled at the base, cylindrical and tapering 

 at the tip ; those of the under part of the body being white and more 

 slender. Ears nakedish. Feet covered with short adpressed hairs. 

 Tail elongate, cylindrical, nearly bald, with rings of square scales. 

 .Skull elongate ; face very much produced, elongate, compressed ; 

 palate rounded in front, flat behind, with an elongated aperture 

 in the middle of its length, more than twice as long as broad ; the 

 hinder part of palate with three equally long longitudinal grooves ; 

 nose flat above ; nasal bones very long, slender. Cutting-teeth white; 

 upper short, with two well-marked subcentral longitudinal grooves ; 

 lower elongated, arched, rather compressed, rounded and smooth in 

 front. Grinders ^^, moderate-sized ; the front much the largest ; 

 the hinder smallest and subcircular ; the front upper rounded on the 

 inner, and with two folds on the outer side; the second upper with 

 one fold on the outer side, the lower front with a slight subcentral 

 fold on the inner side. Crowns of the teeth flat ; the front upper 

 with two and the others with a single cross ridge, less distinctly 

 marked in the hinder teeth. 



Hab. Austraha. 



thrix Uvciira. 



The skull is very much longer and more slender than in any species 

 of Mus or of MuridcB in the Museum Collection. The face is very 

 slender, compressed, flat on the sides and above. The fissure on the 

 side of the nose from the base of the infraorbital foramen is short 

 and small, compared with those in the typical Muridoe. The grinders 

 are nearly erect ; the crowns of the grinders are worn and concave be- 

 tween the ridges of the enamel. 



