LEPIDOTUS. 45 



hinder border of the squamosal and the greater part of the upper border of the 

 opercuhnn. In the specimen shown in PI. VIII, fig. 3, the two inner supratemporal 

 plates are fused together on both sides, while the two outer plates are fused 

 together only on the right side. The exposed face of the post-temporal (PI. VIII, 

 figs. 2 (7, .3 ; PI. IX, figs. 1, 1 a ; PI. X, fig. 3 ; j)^/.) is irregularly triangular in shape, 

 wider than long, with its inner apex extending to the second supratemporal plate; 

 it is also coarsely rugose. The supraclavicle is a deep and narrow plate of bone, 

 fragmentary in the type specimen (PI. VIII, fig. 1, scl.) but well shown in PI. IX, 

 fig. 1, scl. It is truncated and thickest at its upper end where it articulates with 

 the post-temporal ; while^its outer face and hinder border are smooth, except in 

 the upper part, where there is some coarse rugosity posteriorh\ The clavicle is 

 relatively large and curves well forwards, with its narrow exposed portion smooth, 

 only slightly notched at the place of origin of the pectoral fin (PL VIII, fig. 1 ; 

 PI. IX, fig. 1 ; cL). As seen in the type specimen, the anterior edge of the exposed 

 portion is marked as usual by a few rows of small granulations ; and as seen in a 

 detached specimen in B. M. no. 23624, the thin inner or anterior wing of the bone 

 is so wide that the maximum width of the clavicle equals one-third of its depth. 

 The postclavicular plates are smooth, with no enamel except occasionally in the 

 form of a slight tuberculation. The upper postclavicular, which is nearly complete 

 in the type specimen (PI. VIII, fig. 1, pel.), is deep and narrow, and its tapering- 

 upper end bounds the [lower part of the supraclavicle. In this specimen it is 

 tuborculated, but hi the original of PI. IX, fig. 1, it is entirely smooth so far as 

 preserved. The second plate, directly beneath the first, is best seen in the type 

 specimen of L. fitfoni (PI. VIII, fig. 2, pe/.), where it is also slightly tuberculated ; 

 it is nearly as wide as deep, and irregularly triangular in shape with a truncated 

 apex. The series is completed below by two relatively small and narrow plates, of 

 which the lower is the larger and fits into the notch of the clavicle at the origin 

 of the pectoral fin (as shown in PI. IX, fig. 1, -pel.). At least part of the endo- 

 skeleton of the pectoral arch is well ossified, and a bone which may probably be 

 identified as coracoid occurs in the type specimen (PI. VIII, fig. 1, cor.). It is 

 constricted postero-superiorly into a wide and thickened pedicle which ends in an 

 articular facette. Remains of long and slender basal bones or radials are scattered 

 near the pectoral fin in the same specimen, and at least five of these elements in series 

 are also seen in another specimen in the British Museum (no. 23624). As shown 

 in the type specimen, the rather slender pectoral fin-rays have along unsegmented 

 basal part (PL VIII, fig. 1, pet.) ; and the stout, deeply-overlapping fulcra on the 

 anterior ray are in double series, while two relatively large basal fulcra are directly 

 inserted in line with the fin-rays. The number of pectoral fin-rays is unknown. 

 The pelvic fins are much smaller than the pectorals, and inserted nearer to the 

 latter than to the anal fin. They are fringed with a paired row of small fulcra. 

 The dorsal and anal fins are best shown in a fine specimen discovered b}^ Mr. Charles 



