106 WEALDEN AM) PURBBCK FOSSIL FISHES. 



iio-. h. All the principal scales are united by a peg-and-socket joint, which is 

 strengthened by a low vertical ridge on their inner face (PI. XX, fig. 7ft). 



Horizon ami Localities.— Middle Purbeck Beds: Swanage; Upway, near 

 Weymouth. 



2. Pholidophorus granulatus, Egerton. Plate XXI, figs. 5, 6. 



1854-55. Pholidophorus granulatus, P. M. Gr. Egerton, Ann. Mag. Nat. Hist. [2], vol. iii, p. 434 ; 

 and Figs, and Descripts. Brit. Organic Remains (Mem. Geol. Sutv.), dec. viii, no. 4, pi. iv, figs. 1, 2. 

 1895. Pholidophorus granulatus, A. S. Woodward, Catal. Foss. Fishes, Brit. Mus., pt. iii, p. 470. 



Type* — Imperfect fish ; Dorset County Museum, Dorchester. 



Specific Characters. — A very robust species, attaining a length of about 

 30 cm. ; maximum depth of trunk equalling about one-third of the total length of 

 the fish. Head and opercular bones finely tuberculated or rugose, the tubercu- 

 lations extending over the dorsal scales of the abdominal region. Fin-rays smooth 

 and stout, and fulcra comparatively large. Pelvic fins arising far in advance of 

 the middle point of the trunk, and the dorsal fin opposed to them. Scales large, 

 ornamented with very fine oblique ridges, which radiate slightly and end at the 

 hinder margin in delicate serrations ; several series of flank-scales deeper than 

 broad ; lateral line inconspicuous. 



Description of Specimens. — The type specimen displays well the squamation 

 of the trunk and the paired fins ; but it is deepened a little by crushing in the 

 ventral region, and the head bones are broken and displaced. Of the median fins 

 it exhibits only fragments. The other known specimens are still more imperfect, 

 but they show several of the most important characters of the genus and species. 

 One of these specimens (PI. XXI, fig. 5) is interesting as proving that in the 

 abdominal region there is a narrow flattened ventral face between the paired fins. 



The roof of the skull, partly shown in PI. XXI, fig. G, is broad and not much 

 arched from side to side. The parietals (pa.) and squamosals (sq.) are not more 

 than one-third as long as the f rontals, and their external face is closely ornamented 

 with radiating rows of fine tubercles. They are crossed by a groove for the 

 transverse slime-canal, and their hinder margin is deeply overlapped by the 

 supratemporals. Each frontal (fr.) is nearly twice as wide behind as in front, 

 slightly excavated for the large orbit at the outer border, and bifurcating at 

 the front border, where the antero-external angle is less produced than the 

 antero-internal angle, which must have rested on the mesethmoid. The median 

 frontal suture is deeply jagged between the middle of the orbits, but otherwise 

 only slightly wavy. A narrow supraorbital margin is nearly smooth, but the 

 greater part of the frontal is closely ornamented by radiating rows of fine 

 tubercles, which are fused into coarser ridges on the anterior bifurcating portion. 



