IIT. COTTOIDS OF NORTH AMERICA. iy 
narrower at the middle, and broad on both extremities. Four branchiostegals are 
attached to its lower edge. 
The basihyal (41) is situated immediately above and in advance of the cerato- 
hyal; its upper surface is flattened, subtriangular, and even with that of the cerato- 
hyal. In advance of both the ceratohyal and basihyal, a small subconical glosso- 
hyal (42) may be seen. It does not extend into the tongue, which is not prominent 
in these fishes, but remains at the base of that organ, rather to indicate a plan of 
structure than to perform any active function. The thin and flattened urohyal (43) 
is situated between, and extends below, the glossohyal. 
The branchiostegals (44) are six in number, slender, cylindrical, and curved. 
The branchial arches (Fig. 5°) are situated inwardly and behind the hyoidean arch, 
with which they are closely connected: their constituent bones we have now to 
enumerate. 
The basibranchials (45) are not completely ossified; between the hypobranchials 
all along the medial line there exists a narrow band of cartilaginous substance, 
in which we observe small points of ossification, which represent these bones. 
The hypobranchials (46) are entirely ossified; the anterior one is the longest, the 
fourth, or last, is rudimentary, the second and third are soldered together, forming 
a flat expansion with two articulating surfaces, for two ceratobranchials. The 
anterior hypobranchial is flattened in the same manner as the following ones. The 
ceratobranchials (47) are simple, arched, provided on their concavity with small 
tubercles, on which minute needles may be seen. The respiratory fringes oceupy 
their convexity, which is grooved for the passage of the blood-vessel carrying that 
fluid into the fringes. The epibranchials (48) differ very much in shape; the two 
anterior ones are elongated, almost straight, whilst the two others assume an 
irregular trifid appearance. The pharyngobranchial (49), irregularly quadrangular, 
is placed above the epibranchials, giving to the latter their upper point of attach- 
ment. The surface of that bone is beset with card-like teeth, though much smaller 
than those which exist on the jaws. The pharyngobranchial in C@. viscosus is 
symmetrical, that of the left side is perfectly separated from that of the right. 
Besides, we observe here, two others, ovoid, symmetrical pieces (49’) called by 
some inferior pharyngeals, and considered by others as a branchial arch, a cerato- 
branchial, beset with teeth. We leave to further investigation the decision of this 
question. 
For the scapular arch we must return to our F ig. 5". We have already alluded 
to the peculiar situation of the suprascapular (50) which covers the paroccipito- 
mastoid groove articulating with both the paroccipital and the mastoid above, whilst 
to its external edge it holds the scapular. The suprascapular is irregularly quad- 
rangular, provided above with a slender process curved upwards and inwards. The 
scapular (51) is elongated, subtriangular, and thin: The coracoid (52) is crescent- 
shaped, flattened vertically on the middle, and horizontally on both extremities. 
The upper extremity is considerably overlapped by the scapular, and provided on 
the inner edge with a slender and acute spine, on which the latter rests. The epi- 
coracoid (58) is attached to the edge behind the union of the scapular and the coracoid. 
It is a cylindrical, needle-like appendage, which is kept within the thickness of the 
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