CANOBIUS PULCHELLUS. 177 



The length of the head is pretty nearly equal to the greatest depth of the body and 

 is contained slightly more than 4^ times in the total. The shape is fusiform, the 

 body being deepest midway between the head and the commencement of the dorsal I'm, 

 and thence tapering rapidly and elegantly towards the tail-pedicle. 



The cranial roof-bones are ornamented with small rounded tubercles, which some- 

 times tend to become elongated, especially on the posterior or parietal region. The 

 ethmoidal region forms a rounded projection over the mouth ; the orbit is large and 

 anteriorly placed. The suspensorium is more oblique than in Canobius Bamsayi or in 

 C. elegantuius, but less so than in the typical Palaeoniscidac ; the posterior margins of 

 the opercular and subopercular plates pass into each other so as to form a continuous 

 gently curved line. The operculum is a small oblong plate with rounded inferior 

 margin and postero-inferior angle; the suboperculum, nearly equalling the operculum 

 in size, has its upper margin correspondingly concave, and its postero-superior angle 

 slightly produced upwards. The preoperculuin cannot be very distinctly made out, but I 

 rather suspect that it more resembles that bone in typical Palreoniscidas than in 

 Canobius Ramsayi. The maxilla is elongated and its shape is decidedly Palaeoniscid, 

 though its broad posterior part is not so suddenly cut away from the orbit as in more 

 typical forms ; the mandible is slender and tapering, but neither in it nor in the maxilla 

 are any teeth discernible. All the facial bones are ornamented with delicate ridges. 

 usually fiexuous, though on the mandible they are pretty straight, parallel with the 

 inferior margin and touching the superior one at acute angles, owing to the tapering 

 shape of the bone. On the narrow infraorbital part of the maxilla the ridges pass into 

 rows of tubercles, which pass obliquely downwards and backwards or, conversely, upwards 

 and forwards. 



The scales are moderate in size; the median row of scales between the head and 

 dorsal fin is rather conspicuous, but not so much as in C. Ramsayi and C. elegantulus. 

 Taking a flank-scale as an example, the covered area is narrow, the exposed one is 

 ganoid and sculptured with closely-set bold ridges and furrows, forming a pattern, 

 which in its main features is characteristic of a large number of Palaeoniscidas. First, 

 we have a few vertical ridges running close to and parallel with the anterior margin, and 

 then turning round below to run backwards parallel with the inferior one, the rest of the 

 area being occupied with ridges which run parallel with the superior and inferior 

 margins, but of course directed against the vertical portions of the first-mentioned set. 

 Some amount of waviness is frequently observed in these ridges, and, where they come 

 to the posterior margin of the scale, they end in sharp denticulations. On other parts 

 of the body, such as the back, belly and tail, the ridges tend to pass into one set, which 

 traverse the scales somewhat diagonally from before backwards. 



I have not observed the pectoral fins ; the ventral is preserved in one specimen, but 

 shows nothing peculiar in its structure. The dorsal and anal are nearly opposite each 

 other, the former commencing an almost inappreciable distance in advance of the latter; 



