RIIADINICIITHYS FUSIFORM IS. 159 



maxilla is of the usual Palseoniscoid shape and has its broad postorbital portion 

 covered with wavy and contorted ridges, which in most instances pass into a narrow 

 band of irregularly-shaped tubercles stretching along the dentary margin. The mandible 

 is very stout, its depth behind equalling two-sevenths of its length ; in shape it rapidly 

 tapers towards the symphysis. Externally it is covered with closely set, slightly wavy 

 ridges, which, running from behind forwards, diverge from each other along a longi- 

 tudinal line placed rather below the middle of the bone, on whose upper and lower 

 margin they obliquely impinge, but the stricc forming the lower side of this somewhat 

 feather-like pattern are much more horizontal in direction than those on the upper side. 

 The jaws are armed with conical teeth of two sizes, large ones being placed at short 

 intervals inside a row of minute external ones. 



The bones of the shoulder-girdle are striated with tolerably coarse wavy ridges, 

 which, on the upper or vertical part of the clavicle, are again fretted with minute 

 transverse indentations. 



The scales of the body are of moderate size, rhomboidal and tolerably thick. On 

 the front part of the flank (figs. 6, 7) they are tolerably equilateral, with slightly concave 

 upper and convex lower margin; the covered area is very narrow; the articular peg 

 moderate in size, and the keel of the attached surface only slightly developed. Towards 

 the tail (fig. 9) and along the back the scales become smaller and more oblique, and 

 in front of the dorsal fin there are four or five imbricating median scales of a larger 

 size. Along the belly (fig. 8) they become very low and narrow, and on the caudal 

 body-prolongation they are, as usual, small, and acutely lozenge-shaped, while imbri- 

 cating V-scales clothe the upper margin of this part. The scales are marked externally 

 bv a very ornate and easily recognised sculpture, though it is excessively difficult by 

 means of words to give anything like an adequate idea of its peculiarities. It 

 consists of sharp furrows or grooves, sometimes interrupted and intercalated, some of 

 which run parallel with the anterior and inferior margins, while others run more or less 

 diagonally across the remaining portion of the sculptured area. According to the 

 elevation or flatness of the interspaces between these furrows, a greater or less appear- 

 ance of ridging is produced in different specimens (compare figs. 6 and 7), and in all 

 the ridged appearance is pretty strongly developed in the scales of the back between 

 the dorsal fin and the occiput. The ornament becomes less sharp posteriorly, but 

 nevertheless it is developed to a greater or less extent even on the scales of the 

 caudal body-prolongation. Some amount of a tolerably coarse denticulation is also 

 observable, especially on the flank-scales, and, as very commonly happens, it disappears 

 towards the margins of the body and the tail. 



As regards the pectoral tin, I stated in my first notice of this species that so far as 



can be made out by careful examination with a good lens its principal rays seem to be 



articulated up to very near their origins — a feature which would certainly beat variance 



with the characters of Ehadinichthys, and hence I appended a "?" to its position in 



23 



