140 CALIFORNIA ACADEMY OF SCIENCES. 



As no intergradation with other forms has been shown, 

 Professor Cope is not followed in the use of a trinomial. 



Tantilla planiceps (Blainv.) 



Coluber planiceps. 



" 1835, Blainville, Nouv. Anu. Mus., iv, p. 294, pi. 27, figs.3-3b. 

 (1853, Baird and Girard, Cat. N. A. Keptiles, i. Serpents, p. 154.) 



Homalocr anion jAaniceps. 



1854, Dumeril et Bibrou, Eipetologie Generale, vii, p. 857. 



" 1863, Jan. Elenco sist. degli Ofidi, p. 40." 



" 1866, Jan and Sordelli, Icouogr. gener. des Ophid., 15e livr., 



pi. ii, 2." 

 1883, Bocourt, Miss. Sci. au Mex., p. 581, pi. xxxvi, fig. 7-7d. 



Tantilla planiceps. 



(1875, Cope, Bull. U. S. Nat. Mus., No. 1, p. 35.) 



" 1875, Cope, Journ. Ac. Nat. Sci. Phila., p. 143." 



(1883, Yarrow, Bull. U. S. Nat. Mus., No. 24. pp. 13, 190.) 



(1883, S. Garman, Mem. Mus. Compr. Zool. Cambr., viii, 3, pp. 89, 



163.) 

 (1884, S. Garman, Bull. Essex Inst., xvi, 1, p. 31.) 

 (1887, Cope, Bull. U. S. Nat. Mus., No. 32, p. 84.) 

 (1892, Cope, Proc. U. S. Nat. Mus., 1891, p. 598.) 



It is interesting to be able to assign a definite habitat to 

 this long lost species, which has been known from a single 

 specimen collected by Botta, in " California," early in 

 the second quarter of our century. 



There seems to be no doubt that the specimens before 

 me are referable to this name, although they have, with 

 one exception, two postocular plates. 



The head is very flat, and the snout considerably pro- 

 longed beyond the lower jaw. The rostral is somewhat 

 recurved on top of the snout. Behind it are two small 

 internasals, followed by two prefrontals of about twice 

 the size of the internasals. The large frontal presents 

 six edges, but is, in the main, triangular. The parietals 

 are very large, and much broader anteriorly than poste- 

 riorly. The nostril is pierced between two nasal plates, 

 which are united above, but distinct below the nostril. 

 One pre- and two postoculars on each side. The parietal 



