4 WILLIAM K. GREGORY . 
reptiles is the homologue of the lacrimal of the mammals and 
that the reptilian prefrontal should therefore in future be called 
‘acrimale’! since the mammalian and especially the human skull 
is taken for the basis of nomenclature. On the other hand, thinks 
Gaupp, the so-called lacrimal of reptilians and stegocephalians 
has disappeared in the mammals and should be called either 
‘postnasal’ (Jaekel) or ‘adlacrimal’ (Gaupp). 
There is, however, one objection to this conclusion: it is founded 
on a comparison between mammals and recent reptiles and leaves 
the extinct Theriodontia altogether out of account. The lacri- 
mal (adlacrimal of Gaupp) of Cynognathus, Trirachodon, etc., 
in Broom’s recent figures (’11) is similar to the mammalian 
lacrimal in appearance and position, while the prefrontal borders 
the orbit superiorly and has neither the appearance nor the 
position of the mammalian lacrimal. 
In no Cynodont is the lacrimal vestigial, in none is the pre- 
frontal in contact with the jugal as it should be if it were about 
to transform into the mammalian lacrimal. Nor is there any 
suggestion that the reptilian prefrontal has fused with the ‘lacri- 
mal’ to form the true lacrimal of mammals; on the contrary 
the prefrontal may have fused with the frontal to form the 
superior border of the orbit. 
Since the Theriodonts appear to be in every respect closer to 
the mammals than the lizards are,? it seems probable that the 
resemblances between the prefrontal of the lizard and the lacri- 
mal of mammals have resulted from convergent evolution and 
that it is incorrect to homologize the reptilian prefrontal with 
the mammalian lacrimal or to transfer the name lacrimal to the 
prefrontal. 
ORBITOSPHENOID, ALISPHENOID AND EPIPTERYGOID 
Another pair of elements of the reptilian skull whose custom- 
ary name and supposed homology have lately been called: in 
question are the ‘alisphenoids.’ 
Gaupp has shown (’02, ’11) that, in the cartilaginous cranium 
of mammals, the alae temporalis (fig. 2), which are replaced by 
1 ‘Lacrimale’ is etymologically correct (Lat. lacrima, a tear). 
2 See below. 
