136 EDWARD L. RICE 
magnum is the rule in all stages of Eumeces, as also in the croco- 
dile (Shiino, 714). The fissura metotica will be further discussed 
in connection with the otic region (p. 149). 
The roof of the skull in this region was originally named ‘tec- 
tum synoticum’ by Gaupp (’93) and ‘tectum interoccipitale’ 
by Platt (97); later Gaupp (’06) substituted the name ‘tectum 
posterius,’ as leaving open the question of origin and morpho- 
logical relation. The indifferent name is to be preferred. In 
stage 5 of Eumeces a deep groove indicates the boundary between 
occipital arch and otic capsule for some distance above their 
union, as also in Lacerta. By a study of the sections it is easy 
to follow this boundary still further because of the different his- 
tological character of the cartilage—similar to the superficial 
layer immediately under the perichondrium. Finally, however, 
the two masses of cartilage become absolutely confluent and 
homogeneous. Both otic capsule and occipital arch may, then, 
be traced into the tectum without any interruption. In her 
model of stage 2, Miss Cole has shown a deep dorsal notch be- 
tween the tectum on the one hand and the otic capsule on the 
other; the notch is not continuous with the fissura metotica, 
although lying in the line of its extension, In this stage more 
than in stage 5 the conditions indicate an original development 
of the tectum in connection with the occipital arches and a later 
fusion with the otic capsules. From a careful study of the sec- 
tions, I think this interpretation probable, although the undevel- 
oped condition of the cartilage and the indefiniteness of the 
limits of cartilage and connective tissue make an exact deter- 
mination very difficult. In stage 1 the tectum is barely sug- 
gested, and no light is thrown upon its origin. 
A survey of the literature shows the utmost divergence of 
opinion as to the origin and relations of the tectum posterius in 
the reptiles. For the turtles its otic character seems to be dem- 
onstrated beyond question through the work of Gaupp (705 b), 
Kunkel (’12 b), and Nick (712), who show the occipital arches 
with a free dorsal termination and with no connection with the 
well-developed tectum. Gaupp (’05b) holds also to its otic 
character in the crocodile, as does Schauinsland (’00) for Sphen- 
