420 TEiin^. 



29. OPHIOGNOMON. 



Ophiognomon, Cojie, Proc. Ac. Philad. 1868, p. 100. 

 Hapalolepis, Peters, Mon. Berl Ac. 1871, p. 399. 

 Propus, Cope, Proc. Ac. Philad. 1874, p. 70. 



Tongue moderately elongate, arrow-headed. Teeth conical. Head 

 with large regular shields ; frontonasal, pra^frontals, and fronto- 

 parietals absent ; nasals forming a siiture ; nostril pierced in the 

 suture between the nasal and the first labial. Eyes minute, eyelids 

 developed. No ear-opening. Body and tail elongate, vermiform ; 

 limbs rudimentary, the anterior with tubercle-like indications of 

 digits, the posterior reduced to a minute tubercle or altogether 

 absent. Scales smooth, forming regular annuli, and also longitudinal 

 series on the belly ; the dorsals narrow, hexagonal or quadrangular, 

 juxtaposed or slightly overlapping ; the ventrals broader, quadran- 

 gular, juxtaposed. A more or less distinct lateral fold. No collar 

 fold. Males with proeaual pores. 



Upper Amazons. 



Synopsis of the Species. 



Hind limb present, half as long as praeanal 



plates ; 20 scales round the body 1. trisancde, p. 420. 



Hind limb present, reduced to a minute 



tubercle; 26 to 28 scales round the 



body 2. ahendrothii, p. 421. 



Hind limb absent 3. vermiforme, p. 421. 



1. Ophiognomon trisanale. 



Ophiognomon trisanale, Coi)e, I. c. 



Fore limb as long as three anterior labials, with three terminal 

 tubercles ; hind limb styliform, minute, half as long as anal plates. 

 Snout obtuse, slightly projecting. Frontal large, hexagonal, posterior 

 angle prolonged ; parietals larger, obliquely hexagonal, truncate 

 behind ; no interparietal ; two supraoculars ; a square loreal ; two 

 very small infraorbitals ; temporals three, anterior large ; four upper 

 labials, posterior largest ; lower labials three ; mental narrow ; chin- 

 shields, one anterior and three pairs, anterior pair extensively in 

 contact, the posterior smaller and separated from temporals by four 

 narrow plates, and from each other by four plates, the median pair 

 of which are larger and join the anterior pair of chin-shields. A 

 groove surrounds the throat behind the jai;\ s, which is succeeded by 

 five annuli of equal ovate scales ; these are followed by a cross series 

 of six more elongate, which precede a pair of large sternal plates. 

 Dorsal scales hexagonal ; twenty scales round the body and thirty- 

 seven transverse rows between axiUa and groin. Three elongate 

 parallel anal plates. Caudal scales angulate, like dorsals. Below 

 brown ; sides with a brown blackish band, which is bounded above 



