Jordan and Evermann. Fishes of North America. 21 



of caudal ; caudal fin about i of the length, a notch at its tip, opposite 

 last vertebra. Color brown, with small black spots scattered over the 

 body and fins. L. 2 feet. Coast of California ; abundant south of Point 

 Concepcion. Its spirally twisted egg cases are very remarkable. (Name 

 from San Francisco, but its range probably does not extend sc far to the 

 north.) 



,,i frandxfi, GIRAHD, Proc. Ac. Nat. Sci. Phila., 1854, 196, Monterey. 

 Cr*tr<fi,.n /,-,w/.-.r/, CrxTiiER, Cat,, vm, 416, 1870. 



<!ii>; >}>],-n ,;><{n ./>'. w.-ixci, GILL, Proc. Ac. Nat. Sci. Phila., 1862, 492; JORDAN & GILBERT, Synop- 

 sis, ill, 1883. 



21. GYROPLEURODUS QUOYI, (Freminville). 



First dorsal inserted nearer ventrals than pectorals ; anal fin low, not 

 reaching base of caudal; body slender. Brown, with round dark spots 

 about as large as eye. ( Falenciennes.) Galapagos Islands. (To M. Quoy, a 

 French naturalist.) 



Catradon quoyi, FRKMINVILLE, Mag. Zoo'l., 1840, pi. 3, Galapagos. 



Cestracimi paHtherinusi, VALENCIENNES, Voyage de la Venus, about 1850, 320, Galapagos. 

 Cexlrncion quoyi, Gt'NTiiEB, Cat., vm, 416, 1870. 



Suborder GALEI. 

 (THE TRUE SHARKS.) 



Asterospondylous sharks with the palatoquadrate apparatus not artic- 

 ulated with the skull ; gill openings always 5 and always lateral. Dorsal 

 fins 2, well developed, each without spines. This order contains most of 

 the living sharks. (yaAeof, a shark.) 



a. First dorsal fin over or behind the ventrals ; spiracle present ; no nictitating membrane. 

 6. Tail not bent upward ; nostrils not confluent with the mouth. SCYLLIORHINID^:, vm. 

 bb. Tail abruptly directed upward and backward from the base of the caudal fin ; nostrils 

 confluent with the mouth. GINGLYMOSTOMID.S:, ix. 



aa. First dorsal fin inserted more or less in advance of the veutrals. 



c. First dorsal fin long and low, highest posteriorly ; spiracles developed; no pit at root 



of caudal; gill openings all in advance of pectoral. PSEUDOTRIAKID*:, x. 



cc. First dorsal fin high, highest anteriorly, its base wholly in front of that of ventrals. 



d. Caudal fin not lunate, its upper lobe two or more times the length of the lower, with 



a notch below toward its tip ; side of tail not keeled. 

 e. Last gill opening above base of pectoral. 



/. Tail moderately developed, forming less than % of the total length; eyes 



with nictitating membranes. 



g. Head normally formed. GALEID^E, xi. 



gg. Head hammer-shaped or kidney-shaped by the extension of its sides. 



SPHYKNID^E, xn. 



/. Tail exceedingly long, forming about % the total length : eyes without 

 nictitating membrane. ALOPIID.'E, xm. 



ec. Last gill opening entirely in front of pectoral; spiracles pore-like; tail moder- 

 ately developed. CARCHARIIDJE, xiv. 



dd. Caudal fin lunate; caudal peduncle with a keel on each side ; size large. 

 h. Last gill opening entirely in front of pectorals. 



i. Gill openings moderate ; teeth large and sharp. LAMNID.T:, xv. 



il. Gill openings very largo, nearly meeting under the throat ; teeth very 



small; size enormous. CETORHINIU.V,, xvi. 



hh. Last gill opening above the base of the pectorals. RHINODONTIDJS, xvn. 



