AMERICAN LABYRINTHODONTIDM 571 



anteriorly; exoccipitals meeting in the median line in the floor of 

 the skull. Parietal foramen small, subcircular; no auditory notches; 

 orbits very large, subcircular, situated in anterior halfjof skull, and 

 widely separated from each other; premaxillary vacuities large, 

 double, penetrating the roof of the skull at the anterior end of the 

 nares; nares terminal, large, ovate. Base of skull with large quadrate 

 foramina; foramen magnum large, with no inward projections of 

 the exoccipitals. Palatine foramina expanded anteriorly. Teeth 

 with labyrinthine structure much like that of M astodonsaurus ; a 

 large tooth on each ramus of the mandible near the symphysis. 

 Mandible broad and thin, breadth and thickness as 4 to 1 ; a strong 

 postcotylar process present. 



Skull. — The skull of Anaschisma resembles that of Metoposaurus 

 and Capitosaurus in shape. It is subtriangular, with the margins 

 gently convex anteriorly, gently concave in the middle, and again 

 gently convex posteriorly. The roof is almost flat in front of the 

 parietal foramen, but from this foramen the surface ascends rapidly 

 to the posterior margin. The margins of the orbits and nares are 

 not elevated. The lateral arching is considerable posteriorly, 

 including the quadratojugals, jugals, prosquamosals, and postor- 

 bitals. The underpart of the skull is in one plane, save in the region 

 of the quadrates, the inner ends of which descend about 2 cm below 

 the level of the rest. 



The shape of the bones in the roof of the skull is well shown in 

 Figs. 6 and 9. They resemble those of Metoposaurus diagnosticus, but 

 present some notable differences. The premaxillae are more elongate 

 and narrower; the supraoccipitals are shorter; and the epiotics are 

 proportionally narrower and shorter. The suture between the 

 lachrymal and jugal has not been definitely determined, but the 

 lachrymal reaches forward to the posterior border of the nares. 1 

 There is no prominent projection inward of the lachrymal between 

 the orbits and nares. The quadratojugal articulates with the outer 



1 In the January number of the Sitzungs-Berichte der Gesellschaft naturjorschender 

 Freunde, Jaekel attempts to show that the prefrontal of the Reptilia is homologous 

 with the lachrymal of -the Mammalia, and he gives to the so-called lachrymal of the 

 Reptilia the name "postnasal." The evidence that he presents does not, however, 

 seem strong enough to warrant his conclusions. 



