344 ^ SAUEIA. 



regions are whitish or yellowish, with elongated brownish or blackish 

 spots under the head and throat. 



Log. — The species is exceedingly abundant among the sandhills on 

 the coast of Patagonia, where specimens were collected in February, 

 1839, when a colored sketch of the female was made by Mr. Drayton. 



- Plate XVII, fig. 22, represents the profile of the female of Ptyclio- 

 deira gracilisj size of life. 



Fig. 23, exhibits the same specimen, from beneath. 



Fig. 24, is an upper view of the head; 

 . Fig. 25, a front view of the same. 



Fig. 26, the left hand, seen from above. 



Fig. 27, a group of dorsal scales ; 



Fig. 28, a group of abdominal scales. 



Figs. 24-28, are somewhat magnified. 



2. PTTCHODEmA FEMORATA, Grd. 



Spec. Char. — Cephalic plates rugose. Auricular aperture moderate, 

 denticulated. Supralabials much narrower than the labials. Tem- 

 poral scales moderate. Sides of the neck slightly wrinkled. Dorsal 

 scales diminishing in size towards the sides. Abdominal scales 

 smooth, posteriorly rounded. Tail elongated and slender. Brown- 

 ish, with two parallel light streaks on each side, and two series of 

 black spots. Abdomen whitish, unicolor. Inferior surface of head 

 exhibiting interrupted greyish lines. 



^Yia.—Proctotretus femoratus, Grd. in Proc. Acad. Nat. Sci. Philad. VII, 1854, 

 227; &, in Gillis, V. S. N. Astr. Exped. S. Hemisph. II, 1855, 219. PL XL, figs. 5-12. 



Descr. — The head is depressed, and quite declivous from the fron- 

 tal region towards the snout ; viewed from above, it is subtriangular, 

 subtruncated anteriorly. The cephalic plates are of moderate deve- 

 lopment, exhibiting, upon their surface, sinuating, subtubercular ridges, 

 which give to that region a rugose appearance. The vertex plate, a 

 pair of postoccipitals, and two pairs of postfrontals may be distin- 

 guished, amid their number, as larger than the rest. Three post-inter- 



