ESPECIALLY MYCTOPHOIDS gI 
vertical thickened rib on its anterior edge. Like the operculum, the suboperculum 
is ornamented with radiating tubercles. This radiation originates from a thickened 
knob at the antero-dorsal corner of the bone. The ornamentation is most pro- 
nounced ventrally and is absent where the bone lies medial to the operculum. 
Pectoral girdle and fin. The pectoral girdle is shown in lateral view in Text-figure 
40. The post-temporal has a flattened oval upper limb articulating with the 
epiotic. The dorsal surface of this upper limb is ornamented with tubercles radiating 
anteriorly and medially from a point on the postero-lateral region of the upper 
surface. The ventral limb of the post-temporal is approximately equal in length 
to the dorsal limb but is neither expanded nor flattened, simply being a narrow 
strut of bone articulating with the intercalar. Posteriorly the post-temporal is 
produced behind the junction of the dorsal and ventral limbs forming a facet into 
which the medial face of the head of the supracleithrum fitted. The lateral line 
canal entered the post-temporal bone through a postero-medial foramen in the 
anterior region of the supracleithral facet. It ran within a tube to open anteriorly 
in the angle between the upper and lower limbs of the post-temporal. 
The supracleithrum is a long narrow bone with an expanded head housed in the 
medial facet of the post-temporal. The lateral line canal entered the head of the 
bone postero-laterally and left anteriorly within the post-temporal facet. The main 
shaft of the supracleithrum lies medial to the rear margin of the operculum. 
Ventrally it is attached to the lateral face of the upper extent of the cleithrum. The 
outer face of the bone is ornamented with a few longitudinal striations. 
The cleithrum is large with a curved anterior border which is inclined medially to 
form the posterior limit of the branchial opening. The cleithrum narrows dorsally 
and ends medial to the ventral part of the supracleithrum. Ventrally the cleithrum 
is expanded laterally and terminates beneath the preoperculum. The expanded 
lateral region of the bone is ornamented with the characteristic tubercular ornamen- 
tation, while the more dorsal region is extensively ridged. 
The endoskeletal girdle is masked by the lateral cleithral expansion. It does, 
however, project slightly, posterior to the cleithrum, where a scapula and coracoid 
are visible as well as a prominent scapular foramen. A saddle-shaped condyle on 
the rear edge of the scapula provided the articulatory point for the first fin ray. 
The pectoral fin contains approximately 13 rays, all of which are segmented and 
branched distally except for the first ray which does not appear to be branched. A 
small postcleithrum is attached to the posterior edge of the ventral part of the 
supracleithrum. 
Pelvic girdle and fin. The pelvic bone of either side is elongated, narrow and 
tapers to a point anteriorly, but is expanded posteriorly to produce the articulatory 
region for the pelvic fin rays. Medial to this articulatory region each pelvic bone 
bears a prominent horizontal flange which extends into the mid-line to contact its 
partner from the opposite side. The articulatory region consists of a projecting 
lateral condyle, supported by a prominent ridge. The rays of the pelvic fin are all 
segmented and branched distally except for the first ray which does not appear to 
