1922] Notes on the Texas Horned Lizard 137 



At the same time the Iguanid tail shrivels clistally to the more abbre- 

 viated condition of Phrynosoma. Later, stage 33, the surrounding 

 circlet of scales, appearing in the adult around the large dorsal scales, 

 is laid down as an annular anlage, later to be pinched off into its 

 separate scalar elements. 



Pigmentation first appears in the cervical bilateral patches as black 

 markings about stage 35. Kapidly thereafter the pigment appears in 

 the large scalar rosettes caudad. It is interesting to observe that, in 

 the spread of this fundamental scheme of pigmentation, two gradients 

 are to be observed, one spreading caudad, the other laterad. 



As might be expected the horns, characteristic of these lizards, are 

 late in appearing, being seen first with stage 36. 



The newly-hatched young are pale in color, precocial, and may be 

 found within a verj' few days, seeking insect food in the manner of 

 their elders. 



The North Carolina College for Women. 



Greensboro, N. C. 



LITEEATUEE CITED 



Bryant, H. C. : The Horned Lizards of California and Nevada of the Genera 

 Pryuosoma and Anota, Univ. of Cal. Pub. in Zool., g, No. 1 : 1. 1911. 



Jarvis, May M.: The Segregation of the Germ-cells of Phrynosoma cornutum: 

 Preliminary Note. Biol. Bulletin, 15. 1908. 



Peter, K. : Normentafel zur Entwieklungsgeschichte der Zauneidechse (Lacerta 

 agilis) ; (Normentafeln zur Entw. der Wirbeltiere von F. Keibel, Heft 4). 

 Jena, Gust. Fischer, p. 165. 1904. 



Stockard, C. E. : An Experimental Analysis of the Origin of Blood and Vascular 

 Endothelium. II. A study of wandering mesenchymal cells on the living 

 yolk-sac and their developmental products : chromatophores, vascular en- 

 dothelium, and blood-cells. Amer. Jour, of Anat. 18, Nos. 2 and 3, Sept, 

 and Nov., 1915. 



Strecker, J. K. : Notes on the Breeding Habits of Phrynosoma cornutum and 

 Other Texas Lizards. Proc. Soc. Washington, 21:165, 1908. 



Winton, W. M. : A Note On Distinction of the Sexes in Phrynosoma. Science, 

 N. S. 1026:311. 1914. 



