5S 



ORDER CHONDROSTEI — STURGEONS. 



The four species catalogued from this coast, have dwindled to twa 

 upon further examination. Acipenser hracliyrhynchus, the large 

 short-nosed sturgeon, of the Bay of San Francisco, proves to be 

 identical Avith A. transmontamis of the Columbia River; while the 

 A. acufirostris or sharp-nosed sturgeon of Ayres is the young of the 

 same species. 



The only other species, although no sharper-nosed than the pre- 

 ceding, must bear Ayres' name of medirostris, while the A. acutirostiis 

 of Gunther (Cat. Fish. Brit. Mus. VIII. 344), and the A. agassizii of 

 Dumeril, are but the young of this species. Both have the snout 

 acutely pointed when young, and becoming more bluff with age. 



Acipenser transmontanus, White or Common Sturgeon — This stur- 

 geon is common in all bays and large rivers from San Francisco 

 northwards, and is taken in great numbers on the Sacramento,. 

 Columbia, and Fraser Rivers. It feeds to a considerable extent on 

 Crustacea, and Fraser River gorges itself with the eulachon. 



It runs up the rivers in the spring with the salmon. It reaches 

 eight, ten, and even twelve feet in length, and a weight of six hun- 

 dred pounds, but most of those brought to market are much 

 smaller, from twenty-five to fifty pounds. The flesh is largely con- 

 sumed in this city, and is very cheap. Much of it is smoked. The- 

 eggs are used as caviare, and are much esteemed bj^ Germans and 

 other Europeans. 



Acix)enser medirostris, Green Sturgeon — The distribution and 

 habits of this species are the same as those of the preceding, but it is- 

 much less abundant, and though a large species, is probably inferior 

 in size. It is not eaten, as it has the reputation of being poisonous. 

 The smaller number of plates in the lateral line, the greater striation 

 of all the plates, and the different position of the anal fin, are char- 

 acters by which it is easily distinguished, to say nothing of the green 

 color of the flesh, which is probably the cause of its bad reputation 

 and certainly prevents its sale as " sea bass." The flesh is in reality 

 as good as that of the white sturgeon. 



CLASS — ELASMOBRANCHII. 



The Elasmobrancliii, or Sharks and Rays, are fishes of a generalized 

 type, difl'ering widely on the one hand from the true bony fishes, and 

 on the other from the far less organized lampreys and myxines. In 

 the days when it was believed possible to arrange all the forms of life 

 in a straight line, ascending or descending, naturalists were puzzled 

 to know where to place these creatures. In some part of their struc- 

 ture they seem to be as far above true fishes as in others they are 

 below it. The brain is in many respects superior to that of a typical 

 fish, such as a perch or salmon, and the arrangements for securing 

 the reproduction of the species approach in complexity those of the 

 mammalia. On the other hand, the skeleton is cartilaginous and 

 imperfectly developed, and by far the greater number are without a 

 gill covering. The development of the reproductive organs varies 

 greatly in the difierent families and genera of this class; some are 

 oviparous, but produce few and large eggs, while in others the young- 

 are hatched within the body of the mother, and in some species of 

 sharks a rudimentary placenta is formed, the vascular wall of the 



