Batides.- 



-FISHES.- 



-Pristidans. 



167 



B. Second division. — Torpeuixes. — Disc romiJed; very 



blunt in front. Aii electrical apparatus encompassed 

 by the pectoral fins. One family, the Tokpedinid.e. 



C. nird division.— Ei-UE. — Pectorals cohering to the snout, 



the attachment reaching backwards to the ventrals, 

 forming an oval or rhomboidal disc, terminated by a 

 more slender tail than the preceding groups. In the 

 group are the following families : — Kai-edje ; Trygo 



NIDiE; Mi'LIOBATlDJi; and CErUALOPTEKlDJi. 



Family I.— PRISTIDANS {Pristida:). 



The members of this fimiily have nearly the form of 

 those sharks whoso pectoral fins are distinctly separated 

 from the head and do not reach to the ventrals. The 

 snout is elongated and uniform, with stout lateral teeth 

 wliich convert it into a double saw. The true jaw 

 teeth resemble those of tlio Mustclidans, and form a 

 mosaic pavement. The first dorsal stands close behind 

 or partly over the ventrals. The lateral cuticular keels 

 are not continued on the sides of the caudal. Very 

 small, flat, roundish, or hexagonal scales clothe the 

 .smooth sleek skin. The family consists of a single 

 genus (Pristis) of about si.K species called saw-fishes, 

 whose beaks are often seen in museums, but complete 

 specimens are rare. 



Family II.— RIIINiEDANS {Rhinccdcc). 



In these a disc is formed anteriorly by the con- 

 junction of the pectorals with the snout. The four- 

 cornered pectorals do not reach the ventrals, and are 

 separated by a notch from the cephalic part of the disc. 

 The lateral caudal keels are continued on the sides of 

 the bilobate caudal, whose upper lobe is rather the 

 largest. The margins of the jaws arc undidated, three 

 eminences of the lower one corresponding to as many 

 hollows in the upper one. The nostrils are longitu- 

 dinal slits near the mouth, with a flap abo\'e and 

 below. 



Tlic genera are — Ehhm and lihhicholutus. 



Family III.— EUINOBATIDS (R/dnobatidw). 



The ventrals in this group are close behind the pec- 

 torals, which pass imperceptibly into the snout, without 

 the notch of the Ehina;dans. The two dorsals situated 

 on the hinder part of the tail are equal in size, and the 

 caudal has no under lobe. The keels commencing 

 behind the ventrals converge towards the upper edge 

 fo the caudal. The transverse mouth is straight or 

 gently arched. The flat quincuncial teeth are traversed 

 by a cross ridge. The spout-holes are close beneath 

 the eyes, and there is a row of pores beneath the 

 Bcapulo-coracoid girdle. 



The genera are — IHiinobutus ; Si/rrJiina; TrygoKorhina ; and 

 Phdtjrhina; all of them foreign to our seas. 



A " Snow-Csh" of great rarity, whose skin is prized 

 greatly in Assam as a valued medicine, was recognized 

 by IMr. Blyth as a JUdnokitus. Tlie Gunghall or 

 Snow-fish of Kunawar is thought by some naturalists 

 to be a buiTowing lizard. It is described by the natives 

 as having four legs and a human face. 



Family IV.— TORPEDINIDS {Torpedinida). 



In the members of this fiimily a galvanic battery 

 occupies the spaces between the skull and the pectoral 

 fins on each side, and as usual in electrical fishes the 

 skin is quite smooth, developing neitlier ordinary scales 

 nor acute spines. The disc is rounded, very obtuse 

 anteriorly, and termmates posteriorly in a tail, which is 

 less fleshy than that of the two preceding species, and 

 is provided with a sub-triangular caudal. The dorsals 

 are either absent, or there is one or two situated in the 

 tail, and the ventrals are close behind the pectorals. 

 A longer or shorter keel exists on the side of the tail. 



The following genera enter the family — Torpedo ; Narcine » 

 Astrape ; Temera ; Discoiyyge ; and Ilemigalcus. Two species 

 of Torpedo are natives of the British seas. 



Family V.— RAIANS {Rakcdm). 



In this numerous family the disc is rhomboidal, the 

 lateral angles being formed by the meeting of the proxi- 

 mal and distal margins of the pectoral fin of each side ; 

 the snout being a third angle of the rhomb, and tlie 

 origin of tlie tail the fourth. The attachments of the 

 pectorals extend from the roots of the ventrals to the 

 snout. The orbits are separated from the spout-holes 

 by slender cutaneous bridges ; and each of the nostrils, 

 wliioh are on the ventral aspect, is protected by a free 

 rounded lobe of the nasal fiap, as it projects laterally 

 from the even surface of the upper lip. The flat teeth 

 acquire a central cusp in the adult fish in the season of 

 reproduction. Two small dorsals are situated towards 

 the end of the tail ; and the caudal is either absent or 

 exists merely in form of a cuticular seam. The skin 

 is smooth or prickly. 



The genera are — Rai(E ; Sympteri/gia ; and Urapttra. 



Eight diflcrent species of Skates {liaicu) inhabit llic 

 British seas, and furnish much wholesome nourishment 

 to the popidation. 



Family VI.— TRYGONIDS {Trtjgomdw). 



In tills family the nasal flaps are not lost in the upper 

 lip 80 as to form one even surface between the nostrils, 

 but have a common free ledge with short fringes, which 

 is attached to the upper jaw by a mesial bridle only, 

 while the rounded lateral ends project over the nostrils. 

 Under the flap the nostrils approach each other, and 

 there is no valvular lobe on their exterior sides. The 

 large spout-holes are close behind the eyes, which have 

 adnate eyelids. The teeth are transversely elliptical, 

 and have a rounded cross ridge, with either an acute 

 root or one divided into points. The ventrals are 

 8im[)le. The tail is thin and often taper-pointed, witli- 

 out lateral cutaneous keels. It has no caudal or other 

 kind of fin either before or behind a barbed spine, or 

 spines, which it sometimes bears, sometimes wants. 



The genera which enter the family arc — Anacimthus ; Vro- 

 gymnus ; Trygim ; Pteroplatea ; Uypolophus ; Tasniura ; Vro- 

 Inphus; Trygojuiptera ; and .^lojdaiea. 



The Sting- ray or Fire-flaire {Trygon pastinaca) is 

 a British species. 



