176 OPHIDIA. 
Hab. Mexico, Toluca, Guadalajara (Cope), Tehuantepec (Sumichrast); GUATEMALA, 
Pacific Coast (Salvin); Satvanor (Dow); Costa Rica, Cartago (Mus. Brit.). 
The scales of the median dorsal series are not broader than long or even longer than 
broad, In the scutellation of the head this species varies as much as Dipsas cenchoa, 
but the variations do not coincide with the geographical distribution of the species. 
In the type-specimens the spots on the body numbered about forty-two, and were 
connected by a median dorsal vitta. 
A variety is stated to have the very numerous dorsal spots extending entirely across 
the back and sides. 
In our specimens the spots are likewise exceedingly numerous, disposed in three 
series—one of larger ones of rhombic shape along the back, the two others running 
along the lower part of the sides. The spots have a light centre, scarcely darker than 
the ground-colour, and dark brown edges. 7 
3. Dipsas splendida, sp.n. (Tab. LVI. fig. A.) 
Hab. Mexico, Yucatan (Mus. Brit.). 
The scales of the median dorsal series are enlarged, but longer than broad ; scales in 
seventeen series. Habit less slender than Dipsas cenchoa; head small; occipitals but 
little longer than vertical ; loreal longer than deep; one anterior ocular, not reaching 
the vertical; two postoculars ; eight upper labials, the third, fourth, and fifth entering 
the orbit; temporals 14+2-+3; posterior chin-shields about as long as anterior; | 
ventrals 223. Ground-colour of the body brownish grey; body with about thirty-five 
brownish-black rhombic spots, which are produced in the median line forward and 
backward so as to nearly touch the preceding and succeeding ; laterally each spot is 
continued downwards to the ventral scutes; each spot has very clear edges of white ; 
the ground-colour forms an uninterrupted collar on the neck. 
One female specimen, 28 inches long, of which the tail takes 7. 
4, Dipsas tenuissima. 
Himantodes tenuissimus, Cope, Proc. Ac. N. Sc. Phil. (1866) 1867, p. 317. 
Hab. Mexico, Hacienda Santa Gertrudis (A. C. Buller), Yucatan (Mus. Brit.). 
The scales of the median dorsal series are small like the others, which are arranged 
in seventeen series; anteoculars two or one, postoculars two; upper labials eight, 
the fourth and fifth, and sometimes the third, entering the orbit. Temporals 1 or 2+3. 
Body exceedingly slender and compressed. Ventrals 250; subcaudals 157. Whitish, 
with about fifty transverse black light-edged spots on the body, which approach closely 
on the median line; about thirty-five spots on the tail. 
