62 



in nets and with hooks. Its egg cases, deposited in July, are about a 

 foot in length, and squarish with short tentacles at the angles. It 

 is seldom eaten except at San Francisco, and yields but little oil. 



FAM. TORPEDINIDiE TORPEDOES. 



Torpedo caUfornica is not often taken in the Bay of San Francisco, 

 but is tolerably common in the Bays of Tomales and Monterey. The 

 fishermen in the latter bay do not appear to have seen any very 

 large examples, but in the spring of this year one was brought to this 

 city from Tomales Bay of the respectable length of three feet and 

 half an inch, and measuring two feet across the disk. The width 

 across the ventrals was thirteen inches, the eyes were three inches 

 apart, and the spiracles an inch in length. The Italian fishermen 

 call it Tremulo. When fresh it is of a leaden color above, with darker 

 spots, and white below. 



FAM. RHINOBATID^. 



Rhinobatus produdus, Shovel-nose Shark, Guitar — The name 

 guitar refers to the form of this fish, intermediate between that of a 

 ray and a shark, having the thick tail of the latter, and the expanded 

 pectoral fins of the former. It is tolerably common in the Bay of 

 San Francisco and abundant in those of San Pedro and San Diego, 

 residing on muddy and sandy bottoms, and bringing forth its young 

 in August. It reaches a length of two feet or more. The tail is eaten 

 by the Chinese and Mexicans, but is not valued. Otherwise it is only 

 used as a bait for lobsters {Panidirus). 



Rhinobatus triseriatus, Guitar — This species is much more ray-like 

 in its form than the i:»receding, the disk formed by the pectoral fins 

 predominating entirely over the rest of the body, the hinder portion 

 differs only from that of a skate by its somewhat greater thickness. 

 But the true skates or rays {Raiidaz), are oviparous, while the present 

 species, like the preceding and all the PJiinobatidx, is viviparous. 

 Three or four young are produced in each ovarial sac, and are brought 

 forth in August. It reaches a length of two feet, and a weight of 

 four pounds. It is not used. 



SUB-ORDER SQUALI — SHARKS. 



Until Professor Jordan commenced his researches this year, only 

 nine species of sharks were on record from this coast, of which three 

 only, viz.. Triads semifasciatus, Notorliynchus macidatus, and Hetero- 

 dontus francisi, were peculiar to it. The list is now increased to 

 twenty, but all the newly recorded species are well known forms 

 inhabiting the opposite coast of the Pacific, or more commonly the 

 Atlantic, and Mediterranean also, so that it appears probable that all 

 the species found in the Atlantic will ultimately be found here. 



None of the sharks are used as food by the white inhabitants of 

 this coast, but oil is expressed from the livers of some, and "sharks 

 fins" are sold to the Chinese. In Europe some of the smaller sharks 

 or dog-fishes are eaten. 



Some of the sharks have spiracles, or breathing holes, but others 

 are without them; the dorsal fins are large, usually two in number, 

 and placed upon the body, and an anal fin is usually present. In 



