CHONDROCRANIUM OF EUMECES 203 
distance, and finally fuse continuously in the symphysis; no 
independent cartilage is found in the angle of the symphysis. 
This description applies to all stages studied. 
The general form of Meckel’s cartilage in the reptiles is subject 
to marked variation in correlation with the varying function 
of the mouth. Compare, for example, its heavy structure in 
Emys (Kunkel, 712 b, fig. 27) with its delicate form in Eumeces 
(fig. 4). In the former, the ratio of its diameter, half-way be- 
tween articulation and symphysis, to its length, from articulation 
to symphysis, is about 1 to 7; in Eumeces the corresponding 
ratio is approximately 1 to 28. Two further points call for brief 
mention here—the reduction of the processus retroarticularis in 
turtles, and the structure of the symphysis. In Testudo Bender 
(12) describes the processus retroarticularis as entirely lacking, 
although his figure 23 seems to indicate its presence in rudi- 
mentary condition; in Emys, also, Kunkel (’12 b) describes the 
process as very small, especially in later embryos. As to the 
symphysis, the data show much of diversity and somewhat of 
contradiction. An independent ‘basimandibulare’ in the angle 
of the symphysis is recorded by Parker in Crocodilus (’83) and 
Chelone (’80). Gaupp (05 b) also describes a ‘ziemlich selbst- 
stiindiges Knorpelstiick’ in this position in turtles. In Emys, 
according to Kunkel (712 b), the angle is filled by a mass of | 
cartilage, but this is interpreted as belonging to the rami them- 
selves, and not to an independent cartilage in the sense of Parker. 
Bender (12) denies the presence of a connecting piece in Testudo, 
and Shiino (714) in the crocodile. In the snake (Peyer, 712) 
the rami are in contact at one stage of the development, but 
there is no fusion. 
9. HYOID AND BRANCHIAL ARCHES 
The question of the relation of the columella auris to the 
hyoid arch, already discussed in detail (p. 160 et seq.), will not 
be considered here. 
The balance of the hyobranchial apparatus (fig. 4) agrees 
essentially with the account of Lacerta as given by Gaupp (’05 a, 
05 b). The body of the hyoid consists of an insignificant tri- 
