624 11. LEPTOTYPHLOPIDA 
a.—Tail short, strongly compressed laterally, paddle- 
shaped. 
Hydridz.—p. 891. 
Family 11. LEPTOTYPHLOPIDA: 
There are no large plates on the belly, the body being 
covered everywhere with uniform scales. The head is very 
small and continuous with the neck. The nasal plate reaches 
the margin of the lip. The eye may be seen through the 
ocular plate. One or two large plates precede the anus. The 
tail ends in a small spine. A pelvic girdle is present, but 
there are no external traces of limbs. The lower jaw is 
toothed. 
The small, blind snakes belonging to this family are sim- 
ilar in appearance to the Typhlopide of the Old World and 
tropical America, but differ in several structural features. 
The two genera which occur within the geographic limits 
of this work may be distinguished by the following 
SyNopsis OF GENERA 
a.—Ocular plate in contact above with the median series 
of scales on the head. 
Siagonodon.—p. 624. 
a.—Ocular plate in contact above with a supraocular plate 
which separates it from the median series of scales. 
Leptotyphlops.—p. 627. 
Genus 22. Siagonodon 
Siagonodon Peters, Sitzb. Ber. Ges. Naturf. Freunde, Berlin, 1881, 
p. 71 (type, septemstriatus). 
The body is cylindrical, covered with smooth, cycloid 
scales. The rostral plate is very large, and is recurved on 
both the upper and lower surfaces of the protruding snout. 
The nasal plate is very large; behind it is the large ocular, 
followed in turn by wide parietal and occipital plates. A 
