PHOLIDOPHORITS. 105 



widely apart, are not much shorter than the pectorals ; but each comprises only 

 about 10 rays, the foremost fringed with fulcra which are larger than those of the 

 pectoral and especially stout at the base. In the original of PI. XX, fig. 6, the 

 foremost pelvic fin-ray is ornamented with longitudinal flutings of enamel. The 

 dorsal fin is best preserved in the same specimen, with about 16 smooth rays 

 which rapidly decrease in length backwards. In a larger specimen (Mus. Pract. 

 Geol. no. 28438) there are three or four slender basal fulcra besides conspicuous 

 fringing fulcra above, and some of the fin-rays are marked by a longitudinal 

 line of enamel. The anal fin, which is well behind the dorsal, is comparatively 

 small with 9 or 10 rays, best seen, though crushed, in the type specimen (PL XX, 

 fig. 5, a.). Its fulcra are very slender and deeply overlapping, and its broad 

 articulated rays bear some smooth longitudinal strips of enamel. The caudal 

 fin is also best seen in the type specimen, as already described (p. 102). All the 

 fin-rays are much expanded laminae, obliquely overlapping : their appearance of 

 stoutness, therefore, in the fossils depends upon the direction in which they are 

 exposed. 



Nearly all the scales are conspicuously ornamented with coarse plications 

 ending in sharp prominent serrations. As counted along the course of the lateral 

 line they are regularly arranged in from 40 to 45 transverse series ; and the series 

 above the origin of the pelvic fin comprises 13 or 14 scales, of which the seventh 

 or eighth is crossed by the lateral line. On the flank of the abdominal region 

 about six scales in each series are deeper than broad, that crossed by the lateral 

 line and the one immediately below being especially deepened. The two or three 

 lowest ventro-lateral scales are not so deep as broad ; and one of these seems to be 

 bent along its long axis to form the edge of the ventral surface of the fish. All these 

 scales are very conspicuously ornamented by the oblique pectinations throughout 

 their depth ; but the postero-superior angle is sometimes rounded or truncated, 

 while on the less deepened scales of the caudal region the pectinations gradually 

 become restricted to the lower part and sometimes on the caudal pedicle disappear. 

 Among the rhombic scales of the ventral surface (PL XX, fig. 8) and the dorsal 

 border, there is also sometimes a tendency to similar reduction of the ornament. On 

 the scales of the abdominal region the lateral line is marked only by a posterior 

 notch and an occasional perforation ; but on the rhombic scales in the hinder half 

 of the caudal region (PL XX, fig. 7), it forms a sharp smooth ridge, which is also 

 occasionally perforated in the middle. There is slight irregularity in the 

 arrangement of the scales at the insertion of the paired fins ; and on the inner 

 side of each pelvic fin (PL XXI, fig. 4, plv.) there is a peculiar row of two small scales 

 and a posterior large elongate-oval scale, less ornamented than usual. As shown 

 by the type specimen (PL XX, fig. 5) a large elongate-ovoid ridge-scale, finely 

 rugose but not serrated, occurs on the upper border of the caudal pedicle at the 

 origin of the caudal fin. There are no prominent ventral ridge-scales (PL XXI, 



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