CROCODILTANS, LIZARDS, AND SNAKES. 349 



eiubraces some with one row of large supraocular plates, and some with 

 two; some Avith mucronate, and others with eutire dorsal scales in 

 numbers varying from twenty-five to thirty-five between occiput and 

 groin; specimens with the anterior collar border divided and those 

 where it is entire, and those with blue and those with gray throat and 

 cliin. In the following synopsis of varieties I indicate the localities 

 where they are derived. 



I. One row of large supraocular scales. 



Dorsal scales not mucronat*' ; collar border not interrupted. 



(From .Jalapa.) »*?• f- torqnatHS. 



IT. Two rows of large supraocular plates. 



Dorsal scales not mucronate; collar border not interrupted; nowhere blue. 



S. t.poinsettli. 

 (Four from S. W. Texas, Coin-, and two from uncertain Mexican localities.) 

 Dorsal scales not mucronate; collar with anterior border divided; back dark 

 spotted, sometimes with light borders; chin, throat, and sides blue. 



S. 1. cjianogeni/s. 

 (Seven from Monterey, Nuevo Leon, Cope.) 

 Dorsal scales strongly mucronate; anterior collar border divided, and forming 

 two yellow spots on nape; sides blue; chin and throat not blue. 



S. i. mucronatiis. 

 (Four from Vera Cruz, Sartorius.) 

 Dorsal scales strongly mucronate, a little smaller (eight eiinaliug head); collar 

 very slightly interrupted, borders very pale ; green sides and narrow inferior 



collar blue ; chin and throat not blue S. i.formosus. 



Four from Jalapa, Montis de Oca. 



As in S. t. ciianogenys, but scales smaller ; 8-10 in head ; smaller S.t. minor. 



Two specimens from Dtiges, ? locality. 



Finally, the second form described under ^S*. niehoiof/a.ster may consti- 

 tute another variety approaching the 8. t. iorqnatuH., but with the ante- 

 rior collar border interrupted as in S. t. cyanogenys, and the back 

 s])otted as in S. t. formosus. 



Should the interruption of the collar seen in the 8. serrifer prove to 

 be an inconstant character, that form must be regarded as subordinate 

 to the ;S'. torquatus, entering Section I, but related to the S. t. inucronatus. 

 Should the anterior canthal scale appear in the IS. melanof/aster, uothiug 

 but color will distinguish it from the *S'. /. torqttatus, but the strongly 

 nnicronate scales, and the very different color, which is, however, 

 weakened in importance by the S. t. cyanof/enys with its blue chin and 

 throat. 



The definition of the ^S'. /. torquatus is taken from the type of Peale 

 and Greene, which is, however, in the Museum of the Philadelphia 

 Academy. It is correctly identified and figured by l>ocourt. 



Boulenger in the Catalogue of the Lizards in the British Museum 

 regards the 8. t. formosus as a distinct species, and the S. melanogasfer 

 and S./errariperezi as varieties of the 8. torquatus. He nnites the var. 

 cyanogenys with the war. poinsettii. 



The 8. t. poinsettii is the only form which has been found within the 

 limits of the United States. The 8. t. cyanogenys is found so near to 



