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92 Transactions of the Royal Society of South Africa. 
copula ; so much so that on examining the hyoid apparatus in ventral view 
the hyoid and copula seem to be completely continuous, although on careful 
examination of these parts from the dorsal side a joint is clearly indicated. 
According to the figure given by Mr. Beddard for the Agamid genus 
Chlamydosaurus ('P. Z. S.,' 1905, p. 20), the ventral portion of the hyoid 
presents the appearance of a lateral outgrowth from the copula, no demar- 
cation between the two elements being represented, but Goniocejjhahis, another 
genus of the same family, as figured by Hoffmann in Bronn's ' Tierreich,' 
has a very distinct articulation marking the base of the hyoid arch. 
Whatever may be the significance of the basibranchial processes in 
lizards, there can be no doubt but that the isolated cartilaginous elements 
noticed by Mr. Beddard in Zomirus giganteus (Zonuridae), in Tiliqua and 
Trachydosaurus (Scincidae), and in Gerrhonotus (Anguidae), represent por- 
tions of a branchial arch. According to T. J. Parker, they probably represent 
the epibranchial region of the second branchial arch, and Beddard also refers 
them to the same arch. In any case, they cannot be precisely homologous 
with the bar designated as the second branchial in the Chelonia — an element 
which, as previously stated, may really be the same as the basibranchial 
process of lizards. Their dorsal situation and the absence of any trace of 
connection between these elements and the copula apparently indicate an 
origin from the dorsal portion of a branchial arch, whereas the cornua and 
the basibranchial processes are no doubt derived from the ventral portions 
of the original arches. Further, it seems to me undesirable to refer this 
element to any particular arch at present, as the data available from dissec- 
tion of an adult are insufficient for the purpose. They have no cartilaginous 
connection with any part of the hyoid apparatus, and it seems possible that 
they may be referable to any one of the arches therein represented, or to a 
succeeding arch. I shall therefore refer to them merely as the Epibranchials. 
The results of the examination of a number of S. African lizards in search 
of the Epibranchials can be briefly recorded as follows : 
Agamidae. — The epibranchials are absent. The whole hyoid apparatus in 
Agama atricollis is somewhat reduced, both cornua being rather short, and 
the hyoid being quite separated from the tympanic region. 
Varanidae. — In Va,ra7nis the epibranchials are absent ; the hyoid has no 
relation with the ear ; the first branchial is greatly elongated. 
Chamaeleonidae. — The epibranchials are absent in Chamaeleon quilensis. 
The anterior and posterior cornua are considerably reduced. 
Gerrhosauridae. — In Gerrhosaurus validus the epibranchials are present^ 
being sometimes very distinct and ossified. They lie more deeply than the 
cornua, being separated therefrom by a band of muscles. The hyoid ter- 
minates at a considerable distance from the ear, but a very slender strand of 
ligament passes from its end to the tympanic region. G. flavigularis offers, 
similar characters. 
