AMPHISBAENIDAE. 215 



The ground color is olivaceous-brown. There are dorsal blackish 

 spots disposed upon several irregular , longitudinal series. The head, 

 the inferior surface of the body and tail are unicolor. 



LOG. Specimens of this species were collected up Puget Sound, 

 Washington Territory. 



Plate XXII, fig. 9, represents the profile of Elyaria principle, size 

 of life. 



Fig. 10, the same specimen, seen from beneath. 



Fig. 11, the head, from above. 



Fig. 12, a front view of the head. 



Fig. 13, the left hand from above. 



Fig. 14, a group of dorsal scales. 



Fig. 15, a portion of the granular zone, taken on the middle region 

 of the abdomen. 



Fig. 16, a group of abdominal shields. 



Figs. 11-16, are somewhat magnified. 



FAM. AMPHISBAENTDAE. 



In their external aspect, the representatives of this family resemble 

 so much the serpents that several naturalists have classed them in 

 the latter Order of reptiles. Their internal structure, however, leaves 

 no doubt as to their real affinities with the Saurians or lizards at large. 



Their body is elongated, cylindrical, or subcylindrical, and naked 

 or scaleless. The skin, which is tough, exhibits transverse rings or 

 circular verticils, nearly equal, each of which is subdivided into small 

 quadrangular partitions, somewhat elevated, as tubercles would be, 

 and generally symmetrical. There are no eyelids, and, in some in- 

 stances, the eyes themselves are quite rudimentary and even entirely 

 hidden ; neither is there an external auricular aperture : a feature 

 essentially characteristic of the order of Ophidians or serpents. The 

 limbs are always wanting, the anterior pair as well as the posterior 

 pair; they do not even appear in a rudimentary form, as is sometimes 

 the case in certain serpents. The surface of the head is protected by 

 plates or shields, varying in number and arrangement, according to 



