LIST OF PLATES. 



PlATE I. 



Fig. 1. Phrynonax eutropis, Blgr., p. 22. 

 2. Coluber janseni, Blkr., p. 57. 



Upper and side views of head and neck. 



Plate II. 



Spilotes megalolepis, Gthr., p. 24. 

 Upper, lower, and side views of head and neck. 



Plate III. 



Fig. 1. Coluber frenatus, Gray, p. 58. 



2. Leptoj)his occidentalis, Gthr., p. 111. 



3. nir/romarginatus, Gthr., p. 112. 



Upper view of head and anterior part of body, and 

 side view of head. 



Plate IV. 



Fig. 1. DendropJds bifrenalis, Blgr., p. 80. Upper view of head 

 and neck. 

 1 a. . Side view of head. 



1 b. . Side view of middle of body. 



2. grandocuUs, Blgr., p. 84. Upper view of head 



and neck. 



2 a. . Side view of head. 



