102 RAIID.E. 



length their fore or hinder margins ; each wing being thus very nearly equilaterally 

 triangular. 



Head and nape raised high and convex above the general level ; the former with 

 the sides, in which are situate the eyes and spiracles, steep or vertical, with the 

 fore margin of the wings originating in its middle just behind and below the eye ; 

 and again in front descending rapidly between and before the eyes to the tip of the 

 much depressed, yet thick and greatly prominent muzzle. 



Eyes large and prominent, just before and above the base of the wings, placed 

 laterally at the fore end of a prominent ridge, which forms over and before them a 

 gibbous protuberant eyebrow, on each side of the head, which is a little hollow at the 

 top between the eyes. Muzzle greatly depressed below the level of the head, yet 

 thick ; flat underneath, sharp-edged, somewhat flaccid, soft or fleshy : though gene- 

 rally speaking, broad and rounded, it inclines, especially in young or smaller indivi- 

 duals, and whilst the fish continues fresh and moist, rather to a point or angle 

 at the tip ; as well expressed by Salviani in his figure. In larger or in less 

 recently captured examples, it is blunter and more rounded ; but in all states and 

 stages the muzzle projects conspicuously and prominently before the general out- 

 line of the fore margin. 



Spiracles very large ; each within an oblong elongated ear-like cavity imme- 

 diately behind the eye, on the sides of the head or neck. 



Branchial openings as usual in the Rays, five short transverse slits behind each 

 other, quite underneath the body ; in a row on each side behind the mouth. 



Mouth opening transversely quite beneath at the base of the muzzle in a line 

 with the base of the fore margin of the wings ; closing very compactly, and then 

 resembling a cross bar between two longitudinal ones, as in the letter H ; the 

 large nostrils being at the fore-end of the two longitudinal lines, on a level with 

 the eyes. The fore or upper lip is fleshy and flaccid ; slightly bilobed or retuse 

 in the middle, with the edge thin and ciliate. Lower lip entire-edged, but notched 

 slightly in the middle ; within, thickly marked with slightly waved diverging 

 strise. There are no teeth on the edges of the jaws : but far back, in the middle 

 of the upper, is a single bony plate, nearly flat and smooth, of which the visible 

 part is broader than long, and marked with pale transverse lines^ tvu'ning back- 

 wards at the sides. In the lower jaw is a single similar antagonist plate, but 

 flatter and longer than broad. At the front of the plate in the upper jaw, and 

 lying backwards, is a fleshy flap-like veil or skin, semi-circular or tongue-shaped, 

 and with the edge strongly ciliate ; and behind the plate in the lower jaw at the 

 entrance of the gullet are six short fleshy cilia, in a transverse row or curve. 



Removed from their fleshy integuments, both these bony plates are found to 

 be alike longer than broad, and composed of flattened teeth, arranged in three 

 longitudinal bands, and close-set like a pavement. 



Those of the broad middle band or compartment are in a single row, trans- 

 versely oblong, like the steps of a stair-case, and slightly arcuated in front. They 

 are from four to six times broader than deep or long. The side-compartments are 

 greatly nan-ower, and composed of three rows of small lozenge-shaped teeth, 

 set in a tesselated manner in oblique lines ; the outer ones the largest. In the 

 accompanying plate, these parts are represented as they appear in situ in the 

 recent fish, looking into the mouth. Their structure is illustrated by Mr. Yarrell. 

 They act upon each other somewhat like two mill-stones, and are generally more 

 or less worn or hollowed towards their front. From this resemblance has originated 

 the Provencal name of " Movriues" for these fishes ; as well as their generic one 

 from fivXr] or fjivXoc, a millstone, and /3artc, a Ray or Skate ; and which would be 

 more correctly written Mylobatis, though it may still pass in its present form, 

 deriving it immediately from /jivXiag, molaris. 



