2808 Bulletin ^7, United States National flfnseiwt. 



c. Shoulder girdle : 



The shoulder girdle is exceedingly well braced, the post-temi)oral is 

 widely forked, and strongly articulated to the epiotic processes of the 

 slcull. The supraclavicle is long and slender, its posterior face is hol- 

 lowed out and attached some distance from the upper end of the clavicle, 

 which projects upward. This projecting upper end of the clavicle is 

 braced to the skull by two long bones. The first bone is very slender, at 

 its anterior end it is connected to the exocci2iital ; near its middle it is 

 connected with the posterior end of the post-temporal, at which point it 

 turns at a sharp angle and runs to the clavicle. The second bone is much 

 larger; it is articulated to the basioccipital. Its posterior edge is nearly 

 straight for its whole length, but its anterior edge is produced and much 

 swollen near its middle, and joins the post-temporal over the first bone, 

 then runs to the uijper end of the clavicle. The inner part of the clavicle 

 and the coracoid are thin and pierced by many holes, so that the bone in 

 places is little more than network. The hypercoracoid has a very large 

 foramen; at its posterior edge is a projection which supports a thin bone, 

 probably a dermal bone. The mesocoracoid is well developed. There are 

 4 actinosts; the iirst is long, but they rapidly decrease in size to the 

 fourth, which is short and triangular. The first ray of the pectoral is 

 large at the basal end, and hollowed out; it works directly on the hyper- 

 coracoid. 



d. Branchial apparatus: 



The branchial apparatus is peculiar in the adult, in having gill rakers 

 somewhat resembling the filaments of a feather, on both sides of each 

 arch and on the basi branchial. They meet in a middle line between the 

 arches and unite, forming a continuous lattice-work screen, through 

 which nothing but the very smallest bodies can ])a88. The pharyngeals 

 have no teeth, but have gill rakers similar to those on the arches; thej^ 

 are inclosed in sac-like projections on each side. This description is 

 taken from the skeleton of a large siiecimen 4 feet long. The gill rakers 

 are not united in young individuals. 



e. Other parts : 



The septa- between the myotomes are ossified about ^ an inch under 

 the skin, forming long, slender rays of bone. There is an upper series 

 running from the middle of the sides up on the back, and a lower series 

 from the sides down on the belly, and form a sort of a basket around the 

 the body. Those below have a single branch near the middle of each, tln^ 

 ones above have 2 branches each ; these branches are lost toward the pos- 

 terior end. These bones are not present in the youug. The large caudal 

 fin is attached Aery firmly to the hypural, the long rays of each lobe join 

 the hypural at aliout the same oblique angle, the base of each ray is 

 deeply divided and articulated immovably with the hypural. The middle 

 short rays are all nearly horizontal and are much less fijmly fastened. 

 The first interspinal ray of the anal is hollow and cone-shaped, the pos- 

 terior end of the air bladder runs into it as in the genera Eucinostomus and 

 Calamus. The scales are very thick and closely imbricated; the skin 

 anteriorly is I inch thick. (Jordan, Fishes of Sinaloa, 404-409.) 



