1892.] ^^^ [Cope. 



Besides the family characters, this genus is well distinguished among 

 American lizards by the divided frontal ; the overroofing the temporal fossa 

 by the postfrontal and supratemporal ; the descending process of the 

 parietal ; forms of the xiphoid rods, and forms of the pelvic bones. 



Anniella Gray. 



My observations on this genus are based on specimens from San Diego, 

 Cal., presented to me by my friend, James S. Lippincott. 



The premaxillary has an elongate spine, and the palatal suture pre- 

 sents backwards two concavities separated by a median projection. The 

 nasals are distinct and rather short and wide. The frontals are dis- 

 tinct and ralher wide. The parietal is very large everyway, is 

 single, and has no pineal foramen. The supraoccipital forms a 

 close suture with it, sending forwards a median process for internal 

 gomphosis, and an angle on each side of it. It is coossified with the 

 exoccipital, and is expanded to accommodate the large circle of the 

 superior semicircular canal. The facial plate of the maxillary is large. 

 The prefrontal is above the eye, and is cut off from the postfrontal by an 

 entrant angle only. The lachrymal is small, and is below and separated 

 from the prefrontal. No jugal. Postfrontal crescentic, bounded by both 

 frontal and parietal. Postorbital a caducous scale lying in contact with 

 the posterior limb of the postfrontal. Petrosal with its superior border 

 in close contact with the decurved lateral borders of the parietal, as in a 

 snake. The latter do not, however, descend to the presphenoid, but 

 leave a wide fissure below it which deeply notches the anterior border of 

 the petrosal. Supraforaminal part of petrosal produced to an acute 

 angle, terminating at the parietal border much in advance of the anterior 

 semicircular canal. Body of petrosal perforated by a large foramen just 

 in front of the superior part of the quadrate. No parietoquadrate arch, 

 but a posteroexternal angle of the parietal extending near to the proxi- 

 mal extremity of the quadrate. No distinct supratemporal or paroccipi- 

 tal. Stapes with large disk and short stout columella, with thickened 

 tympanic extremity. Vomers continuous anteriorly, slightly divergent 

 posteriorly ; excavated by a deep groove posteriorly, which terminates in a 

 fossa medially. The external borders of the posterior apices are turned 

 outwards so as to enclose partially the posterior nares below. The pala- 

 tines are short, the groove separating the maxillary from the vomerine 

 processes extending to the suture with the pterygoid, so that the maxil- 

 lary process only appears as the inferior face of the bone. Pterygoids 

 elongated anteriorly, reaching to beyond the middle of the palatine fora- 

 men. They extend directly back to the quadrates, being well separated 

 on the middle line, and abruptly notched on the inner side to receive the 

 short angular basipterygoids. They are separated from the sphenoid by 

 a fissure, and are grooved on the inner side posterior to the basipterygoid. 

 Ectopterygoids present, rather slender, enclosing rather large palatine 



PROC. AMER. PHILOS. SOC. XXX. 138. 2 B. PRINTED MAY 24, 1892. 



