SNAKES OF EAST AFRICA. 627 



3, Loreal not more tlian once and a half as long as deep ; 

 nostril in an undivided nasal; scales very narrow, 

 oblique, keeled, in 19 or 21 rows BisphoUdus. 



B. Pupil horizontal; nostril in an undivided nasal; scales 



narrow, oblique, feebly keeled, in 19 rows Thelotomis. 



IV. Eye small or very small ; head not at all distinct from neck ; no loreal. 



A. Subcaudals in two rows. 



1. One or two upper labials in contact with the parietal ; nasal in contact 



with the rostral. 



Scales in 19 or 21 rows ; no prseocular Calamelaps. 



Scales in 15 or 17 rows ; no praocular ; rostral very large, con- 

 cave below ; a pair of internasals and a pair of prffifrontals . Rhinocalamus. 



Scales in 17 rows; a large, elongate prjeocular; rostral very- 

 large, flat below; prefrontals absent Xenocalamus. 



2. Temporals separate the upper labials from the parietals ; scales in 15 rows. 



Nasal in contact with the rostral ; no praeocular Micrelaps. 



First iipper labial in contact with the internasal ; a prseocular... Miodon. 



B. Subcaudals single ; apneocular; scales in 15 rows Aparallactiis. 



1. Geodipsas, 

 Bouleng. Cat. Sn. iii. p. 32. 



1. Geodipsas vaueroceg^ Tornier, ZooL Anz. xxv. 1902, 

 p. 703. 



Usambar-a, German E. Africa. 



2. Pythonodipsas, 



Gunth. Ann. k Mag. N. H. (4) i. 1868, p. 425 ; Bonleng. Oat. 

 Sn. iii. p. 45, 



1. Pythonodipsas carinata Giinth. t. c. p. 426, pi. xix. tig. K; 

 Bouleng. 1. c. 



Zambesi, Damaraland. 



3. Tarbophis. 



Fleischm. Dalm. nov. Serp. Gen. p. 17 ; Bouleng. Gat. »Sn. iii. 

 p. 47. 



Two species: — 



Scales in 19 rows; anal divided T- semianuulatus. 



Scales in 21 rows (rarely 19) ; anal entire T. guentheri. 



1. Tarbophis semiannulatus. 



Telescopus semimmulatus A. Smith, 111. Zool. 8. Afi'., Kept, 

 pi, Ixxii. 



Tarbophis semiannulatus Bouleng. t. c. p. 51. 

 Central and East Africa, Angola, S. Africa. 



2, Tarbophis guentheri Anders. Pi^oc. Zool. Soc, 1895, 

 p], xxxvi. fig. 3 ; Bouleng. t. c. p. 52. 



East Africa, Arabia, Syria. 



