58 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



'' Family VI.— SCYLLIID^. 



^'•{The Eoussettes.) 



" Sharks with two dorsal fius, without spines, the first above or be- 

 hind the ventrals. Anal fin j)resent, usually below the second dorsal ; 

 caudal fin rather long, with or without a basal lobe. Tail not keeled. 

 Spiracles present. No nictitating membrane. Last gill-opening above 

 the root of the pectorals. Mouth usually broad, with small teeth, sev- 

 eral series being in function. Teeth with a median cusp, and 1 to 4 

 small ones on each side. Usually a distinct furrow at the angle of the 

 mouth. Nostrils near the mouth, sometimes confluent with it, some- 

 times provided with cirri. Oviparous. Coloration often variegated. 

 The egg cases quadrate, with prehensile tubes at the angles.* Sharks 

 of the warm seas. Genera 8 or 9 ; species about 30. 



"{ScyUUdcr, Giinther, viii, 400-414.) 



"* Nostrils couflueut witli the mouth; caudal beut upwards, with basal lobe. {Gin- 

 glymostomatincE.) 

 "a. Teeth in both jaws iu mauy series, each with a strong median cusp, and one or 



two smaller cusps on each side ; nasal cirri present Ginglymostoma^ 13. 



ti #» jfostrils not confluent with the mouth ; caudal not bent upwards. (ScyUilnce.) 

 "b. Nostrils separated by an isthmus ; no nasal cirri ; tail not serrated. 



, SCYLLIUM, 13 (&). 



" 13.— GINOI.YMOSTOMA Mliller & Henle." (See pagn 18.) 

 " 13 (Z>).— SCYLMUM Cuvier. 

 " (Cuvier Regne Animal ed. 2, 1829 : type ScyUium caiulus Cuv. = Squahis stellaris Gmel. ) 



" Body rather stout. Head more or less short and broad, the snout 

 low and blunt. Mouth rather large. Teeth small, sharp, tricuspid, in 

 about four rows. Labial fold small or obsolete. Nostrils not confluent 

 with the mouth, separated by a broad isthmus from each other, each 

 with a free flaj) and no cirrus. Spiracle moderate, close behind the 

 eye. First dorsal beginning over ventrals ; second dorsal nearly over 

 anal. Tail slender, not much bent upwards. Spotted. Warmer parts 

 of the Atlantic and Pacific. As here understood, distinguished from 

 iSci/IUorJiinus Blainville, 1816 {S. caniculus L.), by the separate nasal 

 valves. {(TxuXXiov, a shark from axuXlw^ to tear.) 



*'* Head very broad and depressed, broader than long. (Cephaloscylliuvif Gill.) 



* In Hetcrodontidw the egg-cases are without tentacles and spirally twisted. Except 

 the ScylUidce and Heterodontidw, our sharks are all ovoviviparous. 



t Gill, Ann. Lye. Nat. Hist. N. Y. 18G1, 412: type Scyllium laticejjs DumeTil. {icE(pa?.r/, 

 head; aiiv2.2.Lov, Scyllium.) 



