55. LTTORHTNCHTJS. 415 



II. llostral shield separating: the internasals ; one pair of chin- 

 shields ; no labial entering the eye. -' ., 



Scales smooth 4. decurtatus, p. 417. 



Scales keeled 5. browaii, p. 417. 



1. Lytorhynchus diadema. 



Heterodon diadema, Dion. ^- Bihr. vii. p. 779 (1854) ; Genais, Mem. 



Ac. Montpellicr, iii. 1857, p. 511, pi. v. tig. 1. 

 Siniote.s diadema, Giinth. Cat. p. 2u (1858); Strauch, Erp. Alg. 



p. 5:{ (1862) ; Boetty. Bo: Senclc. Gc.^. 1878-9, p. Ul. 

 Lytorhynchus diadema, Pe/ei-.t, Mon. Berl. Ac. 18(52, p. 272, pi. — . 



fig. 1 : Boideny. Tr. Zool. Soc. xiii. 1891, p. 145. 

 Chataclilein diadema, Jun, Arch. Zodl. Anut. Phys. ii. 18G3, p. 228, 



and Icon. Gen. 10, pi. vi. tig. 2 (18G5). 

 Catachla?na diadema, Blanf. Froc. Zool. Soc. 1881, p. 678, tig. 



Snout moderately long ; rostral angularly bent, with straight 

 horizontal edge, detached on the sides, the portion visible from 

 above as long as its distance from the frontal ; no lateral cleft in 

 the rostral ; suture between the internasals much shorter than that 

 between the prajfrontals ; frontal nearly as long as its distance from 

 the end of the snout, slightly shorter than the parietals ; a small, 

 squarish loreal ; one or two pra^oculars, with or without a subocular 

 below; two postoculars ; temporals 1 + jJ or 2 + 3; seven or 

 eight uupcr labials, fourth, fifth, or fourth and fifth, entering the 

 eye ; three lower labials in contact with the anterior chin-shields ; 

 posterior chin-shields as long as or a little longer than the anterior, 

 and separated from each other by two scries of scales. Scales smooth, 

 in 10 rows. Yentrals 160-18S ; anal divided ; subcaudals 30-40. 

 Pale buff or cream colour above, with a series of large transverselv 

 rhomboidal dark spots ; a dark median band along the head and 

 nape, sometimes confluent with an interocular transverse band ; an 

 oblique dark band from the eye to the angle of tho mouth ; lower 

 parts uniform white. 



Total length 450 millim. ; tail 00. 



Algerian and Tunisian Sahara, Egypt, Xubia, Arabia, Syria, 

 Persia. 



a. <S (V. 162 ; C. 44). Algeria. 



b. c? (V. 165 ; C. 40). rvramids of Gizeh. Dr. J. Anderson [P.]. 



c. Yg. (V. 164; C. 42). Abou-lfoasli, W. of Dr. J. Anderson [P.], 



Cairo. 



d. 2 (V. 182 ; C. 43). Muscat, Arabia. A. S. G. Jayakar, Esq. 



$ (V. 188; C. 36). Buslii, S. Persia. 



2. Lytorhynchus ridgewayi, 



[P-]- 



Lv 



rtorhynchus ridgewayi, Bonleny. Ann. ^- May. N. II. (5) xx. 1887, 

 p. 413 ; Boerty. Zool Juhrb. iii. 1888, p. 924 ; Boideny. Tr. Linn. 

 Soc. (2) V. 1889, p. 102, pi. xi. fig. 1. 



