680 REPOET OF NATIONAL MUSEUM, 1902. 



a squarish brown spot, darkest on the l)aek, occupj^ing the middle of 

 each segment, these spots being- absent on many of the ventral 

 segments of the posterior half of the bod\^; top of head uniform 

 brownish, except rostral and nasals, which are colorless. 



Dimensions. 



mm. 



Tip of snout to vent 185 



Tail 16 



Diameter of body 7 



Yariation. — The amount of variation in the large series of 19 speci- 

 mens before me is rather insignificant and affects chiefly the arrange- 

 ment of the occipitals. Thev are alwaj^s broader than long, but they 

 are in contact behind the frontal as often as they are separated. One 

 specimen (No. 25540) is rather more aberrant, inasmuch as the ros- 

 tral is elongated backward somewhat imsymmetrically so as to touch 

 the right prefrontal and thi;s prevent the contact between the nasals. 

 In this specimen the temporal is also prolonged downward so as to 

 touch the corner of the mouth with its lowest point. The number of 

 rings varies only between 220 and 230 in a series of at least 20 speci- 

 mens; the dorsal segments vary between 14 and 16, and the ventral 

 segments between 16 and IS. The number of postgeneials is invaria- 

 bly 3, of anal shields 6. 



Ilahltat. — ^The true Amplushse.na cseca has thus far only been found 

 in Porto Rico, where it seems to inhabit tho lowlands and the moun- 

 tain sides, possibly as high up as 1,000 feet altitude. In the eastern 

 end of the island we collected it on the Catalina plantation, on the 

 northern flank of El Yunque, at an altitude of about 890 feet, while 

 in the west Mr. Baker obtained it at Lares. Mr. J. Michaelis, in 

 1900, sent a specimen to the Hamlnirg Museum from Arecibo. We 

 found it under stones, burrowing like earthworms, or in ants' nests. 



List of specimens of Amphishxna cxca examined. 



