III. COTTOIDS OF NORTH AMERICA. 17 



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 (4G) 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 occupy 

 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 Fig. 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 inastoid 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 

 3 



