AKT. 16 THE GENUS PLAGIODONTIA — MILLEE O 



spaced that they might readily escape notice. The epidermis of the 

 tail is faintly and irregularly divided into tilelike plates about 1 mm. in 

 diameter. In some individuals these plates are so poorly developed 

 that, over large areas, their outlines practically disappear, in others 

 they are rather definitely arranged in irregular rings the posterior 

 edges of which are enough raised to suggest a slight inbrication. The 

 fur is deeper and less coarse than that of Geocapromys hroivni, and 

 the light rings on the dorsal hairs are less contrasted with the dark 

 elements of the color. 



Color. — General color throughout nearly the wood-brown of Ridg- 

 way (1912), darkening to buffy-brown on chest and belly, and paling 

 to avellaneous on anterior part of throat; inner surface of hind legs 

 and area between them and around base of tail tinged with prouts- 

 brown. On the underparts the light brown is uniform; on the entire 

 dorsal and lateral surface it is finely intermingled with dark brown, 

 much less conspicuously than in Geocapromys hrowni, producing an 

 effect of slight clouding but not of any obvious speckling. In certain 

 lights the longer hairs reflect a silvery gloss. The hairs of the back 

 are all light plumbeous at base (this color not appearing at the surface 

 of the fur). The longer hairs have long dark brown tips, the shorter 

 ones have each a wood-brown subterminal annulation about 5 mm. 

 wide and a very short dark brown tip. On the sides and underparts 

 the basal color tends to lose most of its plumbeous tinge and to become 

 light wood-brown, so that the hairs of the belly are often practically 

 uniform from base to tip. 



Slcull. — The skull (pi. 1, figs, 1, la, Ih) is slightly smaller than that 

 of Geocapromys hrowni, but its general form is not very different. 

 Its chief peculiarities as compared with the skull of the Jamacian 

 animal are as follows. In dorsal aspect: The less breadth between 

 lacrimals and at level of anterior zygomatic root as compared with 

 that at the coronal suture and across posterior zygomatic region; 

 the more anterior position (mostly in front of the middle of orbits) 

 of the swellings caused by the frontal sinuses; the more sharply defined 

 postorbital process. In lateral aspect: Less depth of rostrum as 

 compared with that of braincase; antorbital foramen about as deep 

 as orbit instead of much deeper than orbit, its upper, outer margin 

 sloping obliquely forward instead of backward in relation to alveolar 

 line; much more slender zygoma, the upper margin of which does not 

 bear an orbital process; jugal slender, without posterior concavity and 

 postero-inferior process; excessively long paroccipital process (its 

 length about double the vertical diameter of auditory bulla instead 

 of slightly less than diameter of bulla). In ventral aspect: Much 

 smaller incisive foramina and narrower anterior zygomatic region; 

 least longitudinal diameter of glenoid surface very slightly greater 

 than transverse diameter instead of about three times as great as 



