THE SALMON FAMILY. 
7 
Vertebral column: neurapophyses cartilaginous to which the neural spines are united 
merely by suture or mobile articulation, and loosely to each other, anteriorly right to left in 
each vertebra and posteriorly to the diapophysis. Neurapophyses disappearing posteriorly, 
replaced by the bases of the neural spines and connected to the vertebrae by firmer ossification, 
the spines of each vertebra coalescing; diapophyses decreasing and disappearing in the zyga- 
pophyses near the caudal region. The haemapophyses, scarcely evident on the first vertebrae, 
knob-like on the second; and from the third, each furnished with a rib, progressively increasing 
and ending on the caudal region in a succession of haemal spines, each bearing a pair of ribs on 
the posterior upper surface and approaching each other above to form on about the six last 
abdominal and the caudal vertebrae a closed haemal arch. On the haemal-spine-bearing verte- 
brae besides the upper are similar low'er articular processes. Ribs very slender. 
Shoulder girdle: clavicle broad and thin; upper arm comparatively short and the 
posterior consisting of three or four parts, i. e., two or three upper, thin and flat, and one lower, 
pointed, rib-like. 
Pelvis: bones simple, triangular, without notch in front and posterior process rudi- 
mentary. 
Intestinal canal: simple and comparatively short, stomach normally siphonal; pyloric 
and duodenum provided with numerous coeca, directed forward. Coeca varying greatly in 
number in different genera and species; near the diaphragm the intestine abruptly turning 
backward and extending straight to the vent. 
Liver: right lobe very small, left large; duct of the large gall bladder opening into the 
duodenum near the pyloric end of the stomach. 
Spleen : large except for some time following the spawming function. 
Kidneys: kidneys lying along nearly the whole length of the vertebral surface of the 
spinal column, penetrating to some distance into the haemal canal of the tail. 
Testes: furnished with vasa deferentia. 
Ovaries: have no special oviduct opening directly into the genital aperture, but a sort 
of a funnel formed by a fold of the peritoneum, with a slit-like aperture of greater or less extent 
at the posterior portion. 
Air bladder: the pneumatic duct opens on the dorsal side of the oesophagus. 
Recent ichthyological literature at present recognizes six living genera of Salmoninae: 
Oncorhynchus, Salmo, Hucho, Cristivomer, SalveUnus, and Plecoglossus. Of these, four occur 
in North America. The present paper, for reasons hereinafter presented, reduces the number 
of North American genera to three — Oncorhynchus, Salmo, and SalveUnus. They are dis- 
tinguished as follows: 
Oncorhynchus: anal fin comparatively long, of 14 to 17 developed rays; vomer narrow, 
long, flat, with weak teeth; Pacific species breeding but once in a life time and dying soon after 
spawning. 
