Classifica' 

 tion — 

 Rays. 



ICHTHYOLOGY. 



Family I.— PRISTIDiE. 

 Prinides, Mull, and Henle. Form of Sharks, with the gill-open- 



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ings on the ventral surface a*? in the Rays ; characterized by a 

 ' long flat narrow snout, set on the sides with strong bony spines, or 

 teeth forming a saw, with two edges ; true jaw-teeth like those of 

 Mustelns. 



Genus I. Pristis. (Pmt;6aEi5, Blain.) Six species. 



Family II.— RHINOBATID^. 



RhincB, Miill. and ITenle. Of an intermediate form between the 

 typical Kays and the Sharks. Pore part of the body forming a 

 disk by the conjunction of the pectoral fins with the snout ; pecto- 

 ral fins quadrangular, divided from the proper bead part of the 

 disk by a furrow, and not reaching back to the ventrals. First 

 dorsal over the ventrals; caudal bilobate ; upper lobe a little 

 larger ; the keels of the sides continued along the caudal fin. Mar- 

 gins of the mouth undulated ; three protuberances of the under 

 jaw fitting corresponding incurvations of the upper one. Nostrils 

 longitudinal near the mouth, with flaps. 



Genus I. IIiiina, llloch, Schneid. Snout broad, rounded. 

 Spout-holes close behind the eyes. Nasal flaps reaching to the inner 

 corner of the nostril. Undulations of the jaws bold. Teeth almost 

 round, not broader than long. One species. 



Genus II. Rhynchobates, Mull, and Henle. Snout pointed, 

 with a mesial tapering keel. Spout-holes close behind the eyes ; 

 nasal flaps not reaching to the inner corner of the nostril, but only 

 halfway. Undulations of the jaws feeble. Teeth broader than long. 

 A transverse curved row of pores on the ventral aspect of the sca- 

 pular arch. One species. 



Genus III. Rhinobatus, Bloch, Schneid. Pectorals blending 

 imperceptibly with the sides of the snout ; the space between them 

 and the skull cutaneous. Both dorsals on the hinder part of the 

 tail ; ventrals longer than the head, rounded before, pointed be- 

 hind ; no under caudal lobe. Mouth transverse, straight, or 

 gently curved. Teeth pavement-like, with a transverse ridge more 

 or less acute. Spout-holes close behind the eyes. A row of pores 

 on the scapular girdle. Two sub-genera, Syrrhina and Rhinobatus, 

 varying in the e.xtent of the nostril flaps. Eighteen species. 



Genus IV. Trygonorhina, Mull, and Henle. Rkinobati, h\ii 

 the nasal flaps uniting with one another to form a single flap, 

 which hangs over the mouth as in Trygon, leaving a round nasal 

 aperture on each side. Upper eyelid adnate. crescentic; fore mar- 

 gin of the disk with a single incurvature. One species. 



Genus V. Platyrhina, Miill. and Henle. Pectorals approaching 

 one another at the point of the snout, and inclosing the front of the 

 skull. Tail more slender than in the other Rhinohatidce. All the 

 fins rounded. Upjier nasal flap triangular, extending above the 

 inner angle of the nostril. Upper eyelid as in Rhinobatus. No 

 raised edge at the spout-holes. Two species. 



Family III.— TOUPEDINIDtE. 



Les TorpilleSy Cuv. ; Torpedines, Miill. and Henle. Tail short, less 

 thick and fleshy than in the RhinobatidcB, depressed, towards the 

 end cylindrical, keeled on the sides. Disk naked, rounded, without 

 scales or prickles. Ventrals immediately behind the pectorals; 

 dorsals none, or one or two on the tail; caudal sub-triangular. 

 Upper eyelid adnate. A quadrilateral flap, with a free edge between 

 the nostrils, furnishing folds which embrace all the nostril except 

 its lateral corner ; the flap is connected to the upper lip by a bridle. 

 Teeth pointed or flat. A galvanic battery occupying the space 

 bounded by the skull, gills, and pectorals. Teeth flat or cuspidate. 



Genus I. TorpI'DO, Bum. {Narcobatis, Blain.) Two dorsals. 

 Disk rounded, anteriorly truncated evenly or with a slight incurva- 

 ture. Mouth crescentic. Teeth pointed, attached to a jaw cartilage, 

 and not extending outwards beyond the margin of the lips ; base of 

 each tooth widest transversely. Sj)Out-holes at a distance from the 

 eyes, with a cuticular fringe round the orifice. First dorsal bigger 

 than the second one, and situated over the hinder part of the ven- 

 trals; caudal triangular with a straight terminal edge. Four 

 species. 



Genus II. Narcinr, Henle. Two dorsals. Disk roundish, ellip- 

 tical or angular, rounded in front. Mouth small, surrounded by a 

 fold of skin which passes on the mesial line above into the bridle 

 of the nasal flap; this flap is transverse, straight, or with a medial 

 convexity, so as to become faintly tbree-lobed'on the edge ; a labial 

 cartilage above and below. Teeth in quincuncial order, with a middle 

 cusp, forming in the aggregate an elliptical plate, not adhering to 

 the jaw, but moving with the skin ; a velum within the upper jaw. 

 Tail longpr than the disk. Edges of the spout-holes not fringed. 

 Five species. 



Genus III. Artrape, Miill. and Henle. One dorsal. Snout 

 short, without a keel. Mouth as in Narcine. A cylindrical carti- 



lage in the bridle of the nasal flap. Cusps of the teeth on a quad- Classifica- 



rangular base; dental plate overpassing the border of the mouth a tion 



little ; velum within the mouth, above and below. Spout-holes near liavB. 

 the eyes, with smooth borders. Three species. y ^ -^J 



Genus IV. Temera, Gray. No dorsal. Mouth, vela, and nostrils ^ 



as in Astrape. Tail proportionally short. Spout-holes close behind 

 the eyes, with smooth borders. Teeth flat. One species. 



Genus V. Discopyge, Heck. Disk orbicular. Alouth trans- 

 verse, with thick lips at the corners; upper jaw having a dental 

 lamina, turning outwards, covered with minute teeth, in quincun- 

 cial order. Teeth flat, rhomboidal, their hinder angle acute. Nasal 

 valve truncated, with a notched process in the middle; beneath joined 

 by a bridle to the circle of the mouth. Spiracles adjacent to the eye, 

 with naked borders. Ventrals united under the tail; dorsals two, 

 equal; caudals obliquely ovate. 



Genus VI. Hemiqaleus, Bleek. Temporal openings minute, 

 triangular; pupil convex above, narrow beneath. Premaxillary 

 teeth serrated on their outer edge, smooth internally ; mandibular 

 teeth slender, with a broad base not serrated. Conspicuous caudal 

 furrows above and below. Valve of the great intestine rolled up 

 longitudinally. Batavia. Two species. 



Genus VH. Hvpnos, Dum. Disk longish, somewhat notched in 

 the middle of the front border. Spout-holes close to the eyes, sur- 

 rounded by a wreath of long and numerous fringes. No labial 

 cartilages. Mouth crescentic, not protractile. Pointed teeth on the 

 edge of the jaws, whose whole length they occupy, but do not go 

 beyond. Bridle of the nasal flap connected with the fore border of 

 the upper lip. Tail extremely short. 



Family IV.— RAIID^. 



Disk broad, rhomboidal, the two sides which meet to form the 

 lateral angle belonging to the pectoral fins ; these are attached 

 posteriorly, as far back as the root of the ventrals, and flank the 

 point of the snout anteriorly ; dorsals near the tip of the tail. Tail 

 depressed, with a cuticular keel on the sides. Caudal wanting, or 

 existing as a mere cuticular seam. Upper eyelid adnate. Spout- 

 holes separated from the orbits by a slender cutaneous bridge, 

 smooth-edged. Nasal flap confluent with the upper lip, forming an 

 even surface, with a free rounded lobe on each side, that folds over 

 the nasal aperture. Mouth curved, with its convexity towards the 

 tip of the snout ; no labial cartilages. Teeth of the males with a 

 central cusp in spawning time; an upper velum only. Skin 

 smooth, or studded with prickles pointed backwards, among which, 

 chiefly on the dorsal ridge, and on the sides of the tail, there are 

 often larger spines. In the males, sharp prickles are developed on 

 the borders of the pectorals in the spawning season. Oviparous. 



Genus I. Raia, Cuv. {Dasyhatis, Blain.) Snout keeled, with 

 the interior limits of the pectorals parallel to the keel, but sepa- 

 rated from it by a cuticular space. Ventrals deeply notched be- 

 hind, hence bilobate; anterior or outer lobe more narrow. Termi- * 

 nal caudal seam low, and more conspicuous above than below, gene- 

 rally interrupted at the point. Thirty species. 



Genus 11. Sympterygia, Miili. and Henle. Pectoral fins unit- 

 ing before the head and forming the point of the disk as in Trygon, 

 Ventrals not notched, being merely undulated posteriorly; caudal 

 as in Raia. One species. 



Genus III. Uraptera, Miill. and Henle. Snout and ventrals 

 oi Raiai no caudal. One species. 



Family V.— TRYGONID^. 



Tryfjones, Miill. and Henle. Point of the disk formed by the 

 pectorals. Upper eye-lid adnate. United nostril flaps free and 

 fringed, but bound to the upper lip by a slender mesial bridle ; 

 nostrils closely approximated under the flap. Skull higher than 

 in the Rays. Spout-holes large and close behind the eyes. Teeth 

 transversely elliptical, with a ridge which is blunt, sharp, or cus- 

 pidate. Ventrals not notched. Tail slender, often whip-like, with- 

 out lateral keels ; naked, or bearing one or more barbed spines, 

 J^^o caudal. Skin smooth or tuberculated, or prickly. No prickles 

 are developed on the pectorals of the males, as in the Rays. 



Genus I. Anacanthus, Ehrenb. No spine on the tail ; which 

 also wants a fin with rays, but is either naked or furnished with a 

 cuticular seam merely. Two species. 



Genus II. Tuygon, Adan. (Tryjonobatus, Blain.) Disk oval 

 or rhomboidal. Tail equal in length to the body, or longer, 

 bearing one or more spines without cuticular ridges, or with 

 short ones merely, not reaching the point. Teeth cuspidate, or 

 transversely ridged with cross furrows; upper velum deeply 

 fringed with a second crescentic one behind; generally a papilla 

 bfihind the under teeth. The species may be divided by the wholly 

 finless condition of the tail, or the existence of a cuticular seam 

 below, or of a seam above as well as below. Eighteen species. 



