40 U.S. NATIONAL MUSEUM BULLETIN 284 



mens bear two foramina, each on a different cleithral surface, which 

 pierce the cleithrum and, thus, interrupt the canal into which the 

 smaller opening leads. Uncommonly, one of these foramina is absent. 



Each scapula is a small bone applied closely to the internal dorso- 

 posterior surface of its respective cleithrum. A small rodlike portion 

 of each scapula (the dorsalmost portion of the scapula) overlaps its 

 respective cleithrum externally. The tip of this projection stains darkly 

 and seems to lie in a band of cartilage and ligament extending to and 

 along the distal ends of the pectoral radials. There is a small raised 

 process dorsally on each scapula (internal surface) from which a 

 ligament extends to the dorsal midmargin of the respective dorsal- 

 most pectoral radial. The latter process bears an opening at its base 

 that leads into a canal opening into the relatively large median scapular 

 foramen. Along the midposterior margin of each scapula are two en- 

 larged condyles, one above the other. The upper of these processes 

 articulates with the proximal end of the dorsalmost pectoral radial, 

 and the lower articulates with the proximal end of the second to 

 dorsalmost radial. The ventral end of the scapula is joined synchon- 

 drally to the dorsal end of the coracoid. The coracoid has become 

 fused completely with the cleithrum with little or no evidence of a 

 joint. It is represented by a darkly staining synchondral joint with 

 the scapular (above) a long raised condyle on the posterior margin 

 of the cleithrum, which synchondrally joins the proximal ends of the 

 lower two pectoral radials on its respective side, and a mesially pro- 

 jecting spikelike process (the "postcoracoid process" of Swinnerton, 

 1905), which appears to arise ventrally from the cleithrum. Ligaments 

 extend from the process to the ventral surface of the lowermost pec- 

 toral radial. 



There are four pectoral radials on each side. The uppermost on each 

 side is shortest, fanshaped distally, and attached to the upper four 

 pectoral rays; the next lower radial bears a long, slender shank and 

 an expanded distal end that attaches to the fifth and sixth pectoral 

 rays from the dorsalmost radial. The next lower radial is the longest, 

 with a slightly broader head and more expanded base than the pre- 

 vious radial, and attaches to the seventh through ninth pectoral 

 rays from the dorsalmost. This radial attaches proximally to both the 

 scapula and coracoid. The ventralmost radial is hourglass shaped with 

 a well-developed ventral phlange. The distal end of the ventralmost 

 radial attaches to the tenth through fourteenth rays from the dorsal- 

 most. The proximal end of the lowermost radial attaches to the cora- 

 coid condyle. 



The pectoral rays join the radials through cartilage and other 

 connective tissue. The bases of both halves of each ray are expanded, 

 and in the lower half of each fin these expansions gradually take the 

 form of dorsally extending processes that overlap the next ray dorsal. 



