RIIADINICHTHYS TORMOSUS. 155 



distance between the anal fin and tlie commencement of the caudal rather less than the 

 length of the base of the former, 



Descri])t{oit. — The original specimen of this form is represented in PI. XXXIV, 

 fig. 3; unfortunately it is not perfect, as nearly the whole of the upper and a great 

 portion of the lower lobe of the caiidal fin are lost. As it is, the length is 3| inches, 

 but when entire the fish nuist have measured 4^ inches. The length of the head is 

 contained three and a half times in the distance from the tip of the snout to the com- 

 mencement of the lower lobe of the caudal fin, and is ecpnd to the greatest depth of the 

 body between the dorsal fin and the occiput. The cranial roof-l)ones are marked with fine 

 contorted and interrupted striee, and a striated ornament characterises also the facial 

 bones, namely, the maxillae, mandi!)le and branch iostegal rays. I'he dorsal fin is 

 situated l)ehind the arch of the back and more than twice the length of the head from 

 the end of the snout; the anal commences a little further back; both fins are large, 

 triangular-acumimite, with many slender rays which are distantly articulated, the joints 

 being often marked with a dehcate furrow close to and parallel with the posterior 

 nuu'gin. The fulcra on both tins are very well marked. The caudal tin is, as already 

 indicated, broken oft' near its commencement; indications both of pectoral and ventral 

 rays are seen at their proper places, but the fins themselves cannot be described. The 

 scales are moderate in size, those on the flank showing an ornament which resembles 

 that of the last-described species as well as to some extent that of the scales of 

 ElonichtJiys pidch'errimus of the Glencartholm beds, the exposed surface being covered 

 with closely-set ridges, those on the postero-superior part passing obliquely downwards 

 and backwards, while in the antero-inferior aspect they first pass, as fine striae, down- 

 wards ])arallel with the anterior margin, and then, turning at an angle and becoming 

 sharp and prominent, like those above, pass horizontally across the scale to the posterior 

 border. On the hinder border of each scale these ridges end in delicate denticulations. 

 As regards the scales posterior to the ventral tins, the ornament tends to become less 

 pronounced and reduced to a set of grooves passing obliquely across the surface from 

 front to back, but the scales along the origin of the anal fin, and also of the dorsal, as 

 seen in the counterpart, are strongly ridged. All over the body the scales are singularly 

 undisturbed, so that the proportions of the fish are accurately shown. 



In fig. 6 is represented another specimen, which, according to its scale-ornamentation 

 and other details, I identify specifically with the one described above. Its proportions 

 seem, however, at first sight, rather different, the dorsal fin appearing relatively further 

 forwards, the caudal disproportionately large, while the depth of the body at the shoulder 

 is considerably greater than the apparent length of the head. But on a careful exami- 

 nation of the specimen it is evident that these appearances are due to distortion by 

 " shortening up," the scales of the region behind the head being confused, so that the 

 body at this place is, as it were, " telescoped." The specimen measures 4^ inches in 

 length, but I should add at least one more inch to express its original dimensions, so that 

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