13. RHINODONTID^ 
31 
numerous, conical, without cusps or serratures; no nictitating mem- 
brane ; spiracles very small, above the corners of the mouth ; lirst dorsal 
large, midway between pectorals and ventrals ; second dorsal and anal 
small; caudal fin lunate, the upper lobe considerably the larger; caudal 
peduncle keeled; pectorals and ventrals large. A single genus, vdth 
probably but one species ; the largest of living sharks; inhabiting the 
northern seas. {Lamnirhv, pai't, Giinther, viii, 394; genus Selache.) 
29.— CETOKHIIVUS Blahiville, 1810. 
Basl'inrj S harl-ti. 
(Selache Cuvier.) 
(Blaiuville, Bull. Soc. Pliilom. 1810, p. 169: type Ceforhinits f/iuiueri Blumv. — Squulus 
maximus L.) 
The characters of the genus are iueluded above. (.z/Aor, whale ; 
a shark {iSquafina), from /uVyj, a file or ras]), the rough skin of the shark 
being used for polishing wood and marble.) 
39. C. maximtl!!) (L.) Blaiuville . — Basking Shark. 
Body rugose, the skin very rough, with small spines ; head small ; 
snout blunt; eyes small; teeth in six or seven rows in each jaw, about 
200 in each row ; first dorsal large, triangular, over the space between 
pectorals and ventrals ; second dorsal much smaller, rather larger than 
anal; tail large. Largest t)f the sharks, reaching a length of nearly 
forty feet; found in the Arctic seas; straying southward to Portugal 
and Virginia. 
(Squalus maximus L. Syst. Nat.: Selachus maximus Storcr, Fish. Mass. 229: Selache 
maxima Giinther, viii, 394.) 
Family XIII.— RHINODONTIDyE. 
(I' he Whale ^Sharlc.s.) 
Origin of the first dorsal fin somewhat in advance of the ventrals ; the 
second small, opposite to the anal ; both without spines ; a pit at the 
root of the caudal, with the lower lobe of the caudal well developed ; 
sides of the tail tvith a keel; no nictitating membrane; spiracles verv 
small ; mouth and nostril near the extremity of the snout ; teeth very 
small and numerous, conical; gill-openings wide, the last one above the 
base of the pectorals. Large sharks, of warm seas. Two species are 
known, Rhirodon typiem from the Cape of Good Hope, ami the follow- 
ing. {Rhinodontukv Gunther, viii, 396.) 
* Teeth each recurved ))ack\vard and acutely pointed, su'ollen, and with a. hcel-like 
projection in front rising from its base *. MiCRiSTODUS, 30. 
