U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



Measurements. (Taken from dry skins. ) 



Description of a specimen, No. 2212, in alcohol. General form that of S. aquaticus, but larger. 

 Muzzle long, depressed, truncate at tip ; naked for most of that portion anterior to the incisors, 

 or with scattered hairs. The nostrils open antero-superiorly, on a plane oblique to the axis of 

 the muzzle of about 45 ; they are, however, partly visible from the side ; much more distinctly 

 so from above and the end. There is a smooth bulb or gland at the end ; the rest of this muzzle, 

 however, is corrugated ; th*e wrinkles on the lower surface are oblique to the median furrow, 

 and those on either sMe are parallel to each other. 



The eye, though very minute, is not covered by an extension of the skin of the body, as in 

 S. breiveri, but is open to the air ; the orbit, however, is not larger than a pin-hole. It is situ 

 ated so far back that the posterior angle of the mouth falls about midway between the eye and 

 the upper anterior incisor. 



The meatus of the ear is very small and circular, about one-twentieth of an inch in diameter ; 

 there is no external ear. The centre of the meatus is about midway between the eye and the 

 occiput. 



The palms are very large, and broader than long, exclusive of the claws. These are very 

 large and fossorial ; the upper surfaces of the feet are very thinly covered with hair ; beneath 

 they are entirely naked. The tail is about as long as the skull ; it tapers gently to a rather 

 acute tip, and is scantily beset with rather long hairs, which arcely take off the appearance 

 of nakedness. 



The nostrils of this species are more superior than in S. breweri, the palms are proportionally 

 larger and broader. The tail is more acute, and less clothed with hair. The posterior outline 

 of the palm is much less acute, being almost straight, and rounded off at the corners, resem 

 bling the longer outline of an ellipse rather than the shorter, as in S. breweri. The nostrils of 

 S. aquaticus are quite similar in their position to those of S. townsendii. 



In specimens from Petaluma, in excellent preservation, the muzzle is much broader and more 

 abruptly truncate, although the nostrils are as described. The nostrils are crescentic ; the 

 concavity superior ; their anterior extremities approach each other very closely ; they appear 

 rather more terminal than in northern specimens. The size is less ; the palms appear proper- 



