36 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



ORDER E.- 



(The Rays.) 



Gill-openings inferior, slit -like, live in number: spiracles present; no 

 an;il tin: dorsal tins, it' present, inserted on tin- tail; body typically 

 disk-like, broad and Hat. the margin of the disk being formed by the 

 expanded peetnrals. Tail comparatively slender, the caudal tin small. 

 With the exception of the h'tuitla; most or all of the rays are ovo-vivi- 

 parous. (Suborder Jhtfoidci Giinthcr, viii, 434-41)8.) (Latin, raid or 

 rnjn. a ray.) 



Tail comparatively thick, usually with rayed dorsal and caudal lins; no serrated 



caudal spine nor separate cephalic tins. (I'uclnjuru.) 



<i. Snout saw-like, much produced, armed with strong lateral teeth .. I'KISTID.I:, 17. 

 <t<i. Suoul not saw-like. 



b. Disk passing gradually into the long .stout tail: pectorals not extending to 

 the snout ........................................... KHINOBATID.K, 13. 



bb. Disk al)rii])tly contracted at base of the tail. 



<. Klectric organs present; disk perfectly smooth ............ Toi;rr.i>iNii>.K. ll>. 



co, Klectric organs absent; disk and tail more or less prickly ...... RAMD.K. _'(>. 



* Tail very slender, whip-like, ii.s tins, if any, small and near its base. (Mnxlic 

 (I. Pectoral lins uninterrupted, continent around the snout : teeth small. 



iltl. Pectoral lins interrupted, the appendages on the snout (" cephalic lins") 



separate from the pectorals. 

 c. Teeth large, Hal, tessellated .......................... MYIJOIIATIIU;, 'J'J. 



. Tecih very small. Hat or tubercular .............. CKIMIAI.OI-TKKID.K, '2'.i. 



SUPEK-PAMILY PRISTOIDEA. 



(The I'rtNtoiil Itiii/x.) 

 FAMILY XVII. PRISTINE. 



(Tin -sVnr-//.s7/r.s-.) 



Body elongate, depressed ; pectoral lins moderate, the front margin 

 |uite free, not extending to the head; snout produced into a very long, 

 thin. Hal blade, which is armed with a series of strong tooth like pro- 

 cesses along ench edge; teeth in jaws minute, obtuse: gill-openings 

 moderate, inferior; spiracles wide, behind the eye: nostrils inferior; 

 no tentacles ; no nicl itat ing membrane ; dorsal I'm- large, w ithoitt spine. 

 the first nearly opposite the ventrals. Caudal well developed, bent 

 upwards; a fold along each side of tail. A single genus, \\itli live or 



more species, inhabiting warm seas, sometimes ascending the rivers. A 



;amil\ of >hark>. /V/'.v//o/>//or/</^', similarly armed with a ik saw,'' occurs 

 in the I'acilic Ocean. (I'n'.stiilir i ', iinther. viii. l.'Hi 





