voL.xiv,-| PROCEEDINGS OF TlIK NATIONAL MUSEUM. Q] ] 



1891. 



line of the back, we have a lonn like O. d. t/enitilis, as No. 84;;."i, In 7S15, 

 1 ilThi, and 13571 the red only appears on the anterior part of the hotly, 

 and divides completely only a limited nnnilu'r of black rin;,'s behind the 

 head. These approach nearest the O. (j. boyUi. The species further 

 varies in the extent to which the black of the front covers the mu/zle. 

 The latter is whiti; to the posterior part of the prefrontal scuta in 7S|r», 

 8174, and 1()2()0; it is si)eckle(l at the end and on the sides in Sl.T* and 

 4202, and it is totally black in 11753 and 13571. The yellow half collar 

 crosses the ])Osterior p.irts of the parietal plates in t his .species, advan ■- 

 in;;- further forwards than in any of the subspecies of OjiliibnlHsdiiHntnH 

 exceptinj? the 0. d. conjiaictus. 



Th(» increased number of scales on the body and on the tempoial 

 re<i;ion indicate that the altinities of this species are str.>n;;er with tlie 

 (>. (j. hiiiflii than with the (K doliiUiis. It inhabits a hotter and a drier 

 region than the O.boylii, and as the conditions of the country are of 

 later geolojiic orioin than are those of California, the habitat of the 

 (). boi/lii, we may conclude that it is a descendant of the latter. It ap- 

 ])ears in the southern part of California. It illustrates how, under a 

 .semitropical sun, a brilliant color makes its appearance little by little, 

 atid probably in a way totally dilferent from that in which it appeared 

 in the case of the 0. doliatiis (see that species). 



Opliibolus niultistratus K<im. 



Cope, Check List Batr. Kept. N. Aiiier., l"'?'*, i>. 'M. 



f.dntpropeltiH mitUixtratu KtMinicott, I'roc. At-ad. Pliila., 1H()0, p. :Vif<; OphihoUm trianguUin 

 var. mH//i.s/rrt/Hx (laniiaii Mem Miis. C'omp. Zoiil. Caiiiln.. viii. l--:t. p. I''- 

 Central region from latitude KP to Alrxiran I'lateaii. 



Ophibolus getiihia l.,iiiii. 



H(l. and (Jird., Cat. Serp. N. Aiiier., \f*b'i, p. 85; C<»pe, Clu'ck Li»t I?ati. Ii<-pt. N. Amor., 



1^7'), p. :!7. 

 Coliihn-iji'tiilus Linii.S.vst. Nat. i, 17i'.ii, p. :{^-i ; (Jincl. Linn. .syst. Nat. xiii, in, 17-iH, 



p. HOC); Harlan, .lonrii. Acad. I'hila., v, 1827,358; Peale t-onlr. Marlnr. Lye, I, 



I'^-J'.t, IM. v., Giintlier, Cat. Colnhr. .Snakos Hrit. Mmh., K.s, p. 219. 

 I'snidi>i'l(ti>s ijitnlnn Fit/., New ("lass. Kept., \f^iC^, p. 51;. 

 llrriuliMlrijii'i udiiliix Silde;j., Ess. S. 1. Pliys. Sorp., II, ISt?. p. lt)H, 

 ' oroiiclli gvlula Holl.r.. N. Am.T. ILtj... hi, HfJ, ]>. '.C.. PI. '-'1 : niiini. and HiJ.r. Erp. 



(;en. VII, t)17. 

 I ijmprrtpeh'tx <niuUi Copr, i'rur. Aiail. I'liila.. l-ti<». p. -'.'..'.. 



Head little distinct, conical, not depressed, the muzzle slightly com- 

 pressed and the ro.stral plate i)roJecting beyond the lower jaw. Hos- 

 tral plate moderately recurved on the supt lior face of the muzzle. 

 Frontal rather wide, produced posteriorly. Loreal small; oculars 1-2. 

 The ey«' not large, resting on the third ami fourth superior labial.s. 

 Temporal scales, 2-3-4. iSuperior labials seven, higher than l«»ng, excejit 

 the first, sixth, and seventh. Inferior labials ten. ifth longest, post- 

 geneials shorter than pregeneials. Scales in from twenty-om- to twonty- 

 tive rows, rather short, the sizes graduating in.sensibly. Tail short. 



