54 Bulletin ^7, United States National Museum. 



tho body, althougli in advance of the second dorsal. Dorsal spines strong, 

 not grooved. Tail scarcely bent upward. Small sharks abounding in 

 the temperate seas ; 4 or 5 species known. 



The Linmcan genus Squalus was first subdivided by Rafinesque, who 

 restricted the name to those species with spiracles and no anal fin, the 

 type being Squaliis acayifhids. This genus must therefore be called Squalus 

 and not Jcanthia.s. (squalus, shark, a word cognate to the Greek yaly.) 



(I. .Spine of first dorsal about § tbo height of the fin, second about g; some of the wliite 8pots 

 on back usually pernistent through life. acantiuas, 71. 



an. Spine of fir.st dorsal Yi *" Y<. the height of the fin, that of the second dorsal about V^ ; 

 white spots on "back usually disappearing with age. sucklii, 72. 



71. SQIIALTJS ACANTHIAS, Linnteus. 

 (Dogfish; Picked Dogfish; Bonedog; Skittle-dog.) 



Body slender; snout pointed ; head 6i in length ; depth about 8. Dor- 

 sal spines rather high, that of the first dorsal about ?r height of iin, the 

 second dorsal spine about f height of fin. Slate color above, pale below, 

 back with oblong whitish spots, especially in the young, these rarely all 

 obsolete in the adult. L. 2 to 3 feet; weight 5 to 15 pounds. A small 

 sharp-toothed shark, ranging widely in the Atlantic, very abundant along 

 the shores of the Northern and Middle States, and taken as far south as 

 Cuba. From its livers " Dogfish" oil is extracted. It feeds largely on 

 herrings. (axaviJiaf, an old name from a/cflin?a, spine.) (Eu.) 



SquaJnis acanthias, Linn;eus, Syst. Nat, Ed. x., 1758, i, 233, Coast of Europe. 



Squalus acanthias, Jordan & Gilbert, Synopsis, 10, 1883. 



Acnnthias americamis, Stoeer, Mem. Am. Ac., ll, 1846, 500, Massachusetts. 



Acanlhias americmmn, Storeu, Fish. Mass., 232, 1867. 



Acanthias vulgaris, Eisso, Eur. Merid., iii, 131, 1820, Nice. 



Acanthias vulgaris, GiJUTHER, Cat, viii, 418, 1870. 



;2. SQUALUS SUCKLII, (Girard). 



(California Dogfish.) 

 Very similar to the Atlantic species, S. acanthias, but with the dorsal 

 spines lower, the first about i the height of its fin, the second about i. 

 Gray,, the fins usually edged with black ; young with white spots on the 

 back, which u.sually wholly disappear with age. Aleutian Islands to 

 Santa Barbara, very abundant, similar in habits to the preceding, and 

 likewise producing " Dogfish " oil. A similar species, possibly the same, 

 ft. fernandinus (Molina) occurs in Chile. (Named for Dr. George Suckley, 

 a naturalist on the U. S. Pacific R. R. Survey.) 



Spiiiax (Acanthias) siicklii, Giuakd, Proc. Ac. Nat. Sci. Phila., 1854, lOG, Fort Steilacoom, Wash- 

 ington. 

 SiiiiahtssnclcUi, GiLL, Proc. Ac. N.at. Sci. Phila., 1802, 499. 

 Acanthias mchUi, Giuahd, Pacific II. K. Survey, 308, 1858. 



38. CENTROSCYMNUS, Bocage &. Capello. 



Centroscijmnus, Bocage & Capeli.o, Proc. ZoiJl. Soc.,1804, 203, (cixlotepix). 



Dorsal fins each with a spine, which is hidden in the skin ; mouth wide, 

 but little arched; a long, deep, straight, oblique groove on each side of 



