140 FREDERICK TILNEY AND LUTHER F. WARREN 



latter having rod cells, a layer of small cells and a layer of large, 

 probably ganglionic, cells. There is a parietal nerve and a con- 

 nective-tissue strand connecting the organ to the epiphysis. 

 The lens is bi-convex. An accessory organ is also present. 

 There is a capsule of connective-tissue and a broad parietal 

 foramen. A parietal cornea, pit, and spot also exist. 



5. Varanus giganteus. Spencer ('86). 368 In this form there is 

 no mention of an epiphysis. The parietal nerve has a special 

 feature. From the end of the epiphysis to the parietal eye such 

 a nerve is seen to extend. Two or three strands of the nerve 

 are found which become confluent. The parietal eye is dorso- 

 ventrally flattened. There is a lens and retina present, the 

 latter contains rod cells and several other layers. In the cavity 

 there is a vitreus. The lens is thin and bi-convex. In the 

 center is a mass of round cells deeply pigmented indicative of a 

 rudimentary character of the organ. The parietal capsule con- 

 sists of connective tissue. There is a parietal foramen, pit, and 

 spot. 



6. Varanus griseus. Edinger (00). 106 This species shows, in 

 a sagittal section through the brain, an unusually large epi- 

 physis thrown into many folds. It resembles the epiphysis of 

 Pseudopus. 



TEJIDAE. 1. Ameiva corvina. Spencer ('86). 366 In this form 

 neither a parietal foramen nor a corneal pit is present. 



2. Tejus teguixin. Klinckowstroem ('94). 209 An embryo of 

 this form seemed to show only a pineal organ well developed, 

 while above it was a rudimentary parietal eye. Studnicka 384 

 does not believe the parietal eye develops in this form. 



LACERTIDAE. 1. Lacerta vivipara. Spencer ('86) ; 366 Owsian- 

 nikow ('88) ; 295 Strahl and Martin ('88) ; 383 Leydig ('91) ; 238 Stud- 

 nicka ('93). 384 In this species the pineal organ is globular and 

 pyriform; its extremity alone contains pigment. This is con- 

 nected with the parietal eye by a vascular connective-tissue 

 strand. The parietal nerve is independent of this strand. 

 The parietal eye is a flattened vesicle and there is a much-re- 

 duced lumen. The retina is deeply pigmented; its structure is 

 obscured by this vesicle. The lens is bi-convex. The capsule 



