KE VISION OF THE KING SNAKES. 163 



ity of forms in the genus. The important thing to note in all these 

 matters of structure is that annulata is typical of the conservative 

 forms throughout the genus. It is not specialized by having a very 

 short tail (micropJiolis) or very long one (pyrrJiomelaena) , in having 

 the temporals reduced in number (elapsoides, micropholis) or irregular 

 (triangulum) , in having a high number of labials (pyrrliomelaena, 

 conjuncta) or a low number {elapsoides , rJiomhomaculata) , in having 

 unusually short postgenials (boylii, calif orniae), in having a low scale 

 formula (elapsoides, micropJiolis, Jiolhroolci) , or in having a low number 

 of ventrals (elapsoides, gentilis in Utah) . It is near to the normal or 

 average for the genus. 



The pattern, too, is one from which the patterns of all the northern 

 members of the group may be derived. This v/ill be made more 

 plain later on, but it will be well here to describe the pattern of the 

 Puebla specimen (fig. 66), since this is theoretically the most primi- 

 tive in the group (no. 9555, Mus. Comp. ZooL, Puebla, Mexico). It 

 has 19 white (in alcohol) rings on the body and 4 on the tail. These 

 are IJ to 2 scales in width, are a little mottled with darker, chiefly on 

 the sides, and encircle the body. The space between the white rings 

 may be described as black, more or less split with red. The red never 

 extends onto the belly beyond the tips of the ventrals, and dorsally 

 it narrows toward the median line and is frequently excluded there- 

 from by a widening of the black borders. The tail is rmged with 

 black and white. The head is black as far back as the middles of the 

 parietals, anterior temporals, sixth supralabials and fifth infralabials, 

 except for small irregular spots of lighter on the prefrontals and 

 anterior part of frontal, and in the loreal region. This last is sug- 

 gestive of the light cross band on the snout of poly zona, but it is too 

 much to say now what its significance may be. It is expected to be 

 shown that all the forms of the group north and west of annulata may 

 be easily derived from such a pattern as this. 



About all that can be definitely said of the relationship of this form 

 to those inhabiting adjacent ranges is that it is a direct relative of 

 nelsoni, and of gentilis. It is a fairly safe conclusion that inter- 

 gradation takes place with both of these forms. Its relationship to 

 polyzona, judging from the material now at hand, is not at all clear, 

 but it must be close. 



