MORPHOLOGY OF THE VERTEBRATE SKULL 3 
PREFRONTAL, LACRIMAL, ADLACRIMAL 
The prefrontal of the lizard and other recent reptiles has been 
shown by Gaupp (’10) to have the same or nearly the same rela- 
tions with the chondrocranium and with the naso-lacrimal duct 
as has the lacrimal of mammals. The so-called lacrimal of 
Fig. 1 A, The lacrimal region of Lacerta viridis. After Gaupp, 1910, p. 
532. 
The lacrimal (‘adlacrimal’) is vestigial, the prefrontal has the appearance and position of the 
mammalian lacrimal. 
B, Skull of the primitive Cynodont Nythosaurus larvatus. After Broom, 
(1911, text,—fig. 170, p. 899). 
The lacrimal is well developed and has the normal relations of the mammalian lacrimal, the pre- 
frontal is separated by the lacrimal from the jugal; it is in contact with the nasal and lacrimal like 
the anterosuperior portion of the ‘frontal’ of mammals. 
reptiles (which only in the Crocodilia is pierced by the duct) 
is widely removed from the chondrocranium and in the lizards 
is an inconstant element. On these and similar grounds Gaupp 
concludes, with Kober and Jaekel, that the prefrontal of the 
