150 CALIFORNIA ACADEMY OF SCIENCES. 



Suborder IT. SERF ENTES Snakes. 

 Family X. LEPTOTYPHLOPID^E. 



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 

 similar in appearance to the Typhlopidce. of the Old 

 World and tropical America, but differ in several struc- 

 tural features. 



Genus 21. SIAGONODON.* 



" Siagonodon, PETERS, Sitzb. Ges. naturf., Freunde, 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 row of small scales runs along the 

 top of the head behind the rostral plate. No supra- 

 ocular plates are present. The preanal plate is not 

 divided. 



A single species represents this family in California. 

 44. Siagonodon humilis (Baird & Girard). WORM 

 SNAKE. 



Rena humilis, B. & G., Cat. N. A. Keptiles, I, Serpents, 1853, p. 143 

 (type locality Valliecitas, Cal.); STEJNEGER, Proc. U. S. Nat. 

 Mus., XIV, 1891, p. 501; STEJNEGER, N. A. Fauna, No. 7, 1893, 

 p. 203. 



* The type of Rena is R. (=Leptotyphlops) dulcis B. & G. 



