1. ZONDRTTS. 253 



Si/no2>sis of the Species. 



I. Frontonasal in contact with tlie rostral ; scales of the flanks 



separated from one another by granular intervals. 



Head with largo spines posteriori)- . ... 1. <jif/aiitei(s, p. 253. 

 Head without S2)ines 2. tropidostenium, p. 254. 



II. Frontonasal sejjarated from the rostral. 



A. Flanks with scales like the dorsals. 



a. No supranasals ; lower e\-clid opaque. 



Nasal swollen, hemispherical, pierced 



in the centre ; temporal spines .... 3. catcqihractus, p. 255. 

 Nasal not swollen, pierced posteriorly ; 



no temporal spines 4. conhjlus, p. 256. 



b. A supranasal, nasal very small ; lower eyelid with a 



transparent disk. 



Anterior gular scales flat, moderate . . 5. poJyzoims, p. 257. 

 Anterior gular scales almost granular . G. pustulatus, p. 258. 



B. Flanks granular 7. cajpensis, p. 258. 



1. Zonurus giganteus. 



Zonurus derbianiis, Gray, Cat. pp. 48, 270. 

 Cordylus giganteus, Smith, III. S. Afr., Bepf. pis. xxxv., xxxvi. 



Head longer than broad. Head-shields very rough ; frontonasal 

 slightly broader than long, in contact with the rostral, separating 

 the nasals ; latter not swollen, the nostril pierced in the postero- 

 inferior corner ; praifrontals forming a suture ; frontal hexagonal, 

 slightly widened anteriorly ; frontoparietals longer than broad ; 

 interparietal as large as, and on a line with the anterior parietals, 

 forming a suturo with the postfrontals ; posterior parietals much 

 larger than anterior ; four large, striated occipital spines, the inner 

 shorter and- slightly curved inwards, the outer largest, directed 

 obliiiuclv outwards, as long as the three anterior suj^raorbitals ; 

 temporal shields large, keeled; four subtriangular, slightly curved 

 temporal spines on each side, the upper nearly as large as the 

 median occipitals ; supraoculars four, anterior largest, second 

 broadest ; three supraciliarics ; lower eyelid opaque ; a small loreal 

 or ])ostiuisal and a largo i)riieorbital ; two infraorbitals ; sis or seven 

 upper labials, fourth or fifth smallest ; rostral six-sided, twice and 

 a half as broad as high. Mental large, pentagonal ; five lower 

 labials, fifth largest and keeled ; a row of live large shields borders 

 tlie lower labials, and there is a median chin-shield behind the 

 anterior pair ; gidar scales moderately large, subtriangular, strongly 

 imbricate, feebly keeled ; scales on the collar large, lanceolate, 



