20 



they are so brittle and confused with the head; fins, pectoral a little behind gill plates, and 

 extend below the fish 3-lOths of an inch,— it is a narrow-pointed fin, well marked with its rays. 

 Dorsal fin far back towards the tail, a little anterior to anal; it is half an inch long and 2-lOths 

 of an inch high, and is well marked with its rays. Anal fin somewhat larger than dorsal, a little 

 posterior to it. Abdominal fin very small, situated a very little in advance of the middle of the 

 body; tail unequally bifurcated or heterocercal ; scales run down on it becoming smaller and 

 more and more acutely rhomboidal or lozenge shaped as they recede; caudal rays come exclu- 

 sively from under side of upper division of tail. Scales obtusely rhomboidal On anterior and 

 middle of body, and are distinctly striated parallel to anterior and lower margins, while they are 

 smooth and very brilliant towards and upon the tail; dorsal scales large and in form of obtuse 

 spherical triangles pointing backwards towards the dorsal fin. This species is not described 

 in any book I have examined, and believing it to be new, I shall take the liberty of naming it 

 Palceoniscus Cairnsii, after the highly intelligent superintendent of the Albert coal mine, William 

 Cairns, to whose active and unremitting labours I am indebted for so many specimens of these 

 interesting fossils." 



Rhadinichthys alberti is of small size, rather slender, fusiform, averaging in length about 

 8-5 cm. Greatest depth of trunk in advance of the pelvic fins, slightly over one-fifth the total 

 length. The head, in length, about equal to the maximum depth of the body. Eye of moderate 

 size, placed far forward. Fins well developed. Dorsal fin beginning a little behind the mid- 

 length of the fish, triangular, about the same size as, and arising, somewhat in advance of the 

 anal fin. Caudal fin much prolonged in upper lobe, deeply forked. Pectoral fins large, with a 

 short base. Pelvic pair, if anything, nearer to the anal fin than to the pectorals, of small size. 

 Teeth minute. Suspensorium oblique. 



Anterior flank scales, plate III, fig. 5, about as deep as long (exposed surface), ornamented 

 with striations, some of which are parallel to the lower and anterior margins; while others, 

 fewer in number, have an oblique backward and downward direction and are^confined to the 

 upper, posterior quarter of the scale. These latter striations are deeper than the others, are 

 comparatively short, and are most conspicuous toward the back margin. The former are fine, 

 fairly regular, and occupy the remaining three-quarters of the scale surface, bending upward 

 anteriorly parallel to the front margin. There are three or four of the coarser strise and about 

 six of the finer ones. The striations indent the posterior margin of the scales causing it to be 

 minutely serrated. In the more posterior flank scales the striations are fewer in number and 

 tend to disappear, the oblique striae being still apparent when the remainder of the scale surface 

 has become smooth. In these scales the serrations behind are reduced in number and are 

 relatively coarser. In the body prolongation of the upper lobe of the tail the scales have the 

 usual elongated diamond shape, with a surface in which a slight indication of a coarser longi- 

 tudinal striation is still visible. 



About ten to twelve enlarged ridge scales, (plate III, fig. 6,) occur in advance of the dorsal 

 fin, reaching in a row forward to a point not far removed from the back of the head. They 

 are considerably longer than broad, narrowly rounded in front, somewhat pointed behind, and 

 are coarsely and irregularly striated longitudinally, the striations conforming in a general way 



