Coracoid. — Widest dorsally, tapering to a shaft 

 ventrally; with a slender spinelike process under the 

 lowermost actinost from its posteroventral edge; the up- 

 per one-third of its posterior edge with an intumed flange 

 medially; cartilage filled at its dorsal end and at the tip 

 of its ventral shaft; articulates by fibrous tissue and in- 

 terdigitation anteriorly with the cleithrum, which 

 overlies the upper anterior edge of the coracoid; articu- 

 lates anterodorsally through cartilage with the scapula; 

 posterodorsally the edge of the coracoid supports the 

 lowermost and largest actinost and sometimes, to a les- 

 ser extent, the lower edge of the base of the third acti- 

 nost. 



Scapula. — Completely encloses the scapular 

 foramen; cartilage filled at its anterior and ventral edges; 

 articulates anteriorly by fibrous tissue and slight inter- 

 digitation with the cleithrum, while ventrally it articu- 

 lates through cartilage with the coracoid. Along its pos- 

 terodorsal edge the scapula articulates by fibrous tissue 

 with the following elements, in order from anterior to 

 posterior or above to below: the first and uppermost 

 pectoral fin ray attached to a projection from the surface 

 of the scapula, immediately below which the scapula 

 supports on a small flange the small uppermost actinost, 

 with the second and third actinosts articulating along 

 the relatively unmodified posterior edge of the sca- 

 pula, although the posterodorsal edge of the coracoid 

 helps to support the lower basal region of the third acti- 

 nost. 



Actinosts. — Four elements; all cartilage filled at 

 both ends; the first actinost small, the others increasing 

 slightly in size from above to below in the series; articu- 

 lated to the scapula and coracoid as described in the 

 preceding section. Distally the actinosts support by 

 fibrous tissue all of the fin rays except the first, which is 

 supported by the scapula. 



Fin rays. — Twelve fin rays in most specimens, with 

 the first ray about one-tenth the length of the second ray 

 and articulated directly with the scapula, rather than 

 with the actinosts, as are the other rays. First ray with its 

 medial half enlarged and thickened at its basal region of 

 articulation with the scapula; its lateral half reduced to a 

 thin short splint closely held to the medial half. All of the 

 pectoral fin rays unbranched; the first ray without cross- 

 striations, all the other rays cross -striated. 



Pelvic Fin. 



Pelvis. — A stout shaft; not divided into separate 

 right and left halves; anterior three-fourths of its lateral 

 surface with a concavity for muscle attachment; a large 

 relatively slender dorsal lobe present from its postero- 

 dorsal region which serves as a place of tough fibrous 

 tissue attachment for the overlying skin of the highly dis- 

 tensible abdominal area or ventral flap (dewlap). A 

 series of enlarged scales encircle the posterior end of the 



pelvis and obscure from view the rudimentary fin-ray 

 element present in the midline just behind the end of the 

 pelvis. The lateral surface of the posterior end of the 

 pelvis bears several ridges for articulation with these 

 scales. The scales occur in three segments, with only the 

 distal segment movably articulated, the major region of 

 flexibility in the series being between the second and 

 third series. The fin-ray element is reduced to a single 

 nubbin of bone above and below the plug of cartilage that 

 extends posteriorly from the end of the pelvis, as describ- 

 ed in detail by Tyler (1962b:229-232, figs. 38-45). These 

 bony nubbins, representing the remains of a fin-ray (or 

 spinous) element, are closely held by fibrous tissue to the 

 cartilaginous plug. Running anteriorly from each of the 

 nubbins is a tendon. The tendon from the dorsal nubbin 

 courses through a hole in the dorsal flange of the pelvis to 

 attach to a muscle housed in the concave region on the 

 dorsal surface of the pelvis, while the tendon from the 

 ventral nubbin runs along a similar concavity on the ven- 

 tral surface of the pelvis. The fin-ray nubbin and the at- 

 tached plug of cartilage at the end of the pelvis are 

 movable in a dorsoventral plane around the posterior end 

 of the pelvis by the contractions of the muscles on the 

 dorsal and ventral surface of the pelvis to which they are 

 connected by ligament. The pelvis itself is movable in a 

 dorsoventral plane around its fibrous tissue attachment 

 between the ventromedial edges of the cleithra. 



VERTEBRAL COLUMN. —All vertebrae with 

 biconcave centra, except the last, which posteriorly ends 

 in a plate representing the fused centrum, hypurals, and 

 parhypural. 



Abdominal Vertebrae. 



First vertebra. — Neural spine shorter than those of 

 the succeeding vertebrae but sturdy; laterally expanded, 

 bifid to the centrum and thus not forming a bony roof 

 over the neural canal; articulates by extensive interdigi- 

 tation along most of its anterior face with the exoc- 

 cipitals and epiotics. The rim of the concave anterior face 

 of its centrum articulates by fibrous tissue with the rim 

 of the concave posterior end of the basioccipital, while 

 the rim of its posterior face articulates similarly with the 

 rim of the anterior face of the second vertebra. Anteriorly 

 between the region of the centrum and the neural arch, 

 the first vertebra is slightly overlain by the short exoc- 

 cipital condyle. From the lower region of its postero- 

 lateral surface the centrum possesses a short postero- 

 ventrally directed process which makes fibrous tissue 

 contact over the anterior fifth of the lower surface of the 

 centrum of the second vertebra, although this is mostly 

 obscured from lateral view by the lateral flange of the 

 second vertebra. 



Other abdominal vertebrae. —In 12 specimens the 

 abdominal vertebrae numbered six. Except for the first 

 vertebra, all the abdominal vertebrae, as well as all of the 



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