108 WEALDBN AND PURBECK FOSSIL FISHES. 



Fringed with stout Fulcra. The pelvic pair is inserted nearer to the pectorals than 

 bo the anal, directly opposite the origin of the dorsal fin, which begins with 5 or 6 

 very stoul but small basal fulcra, more or less enamelled, and comprises not less 

 than 12 rays, perhaps 2 or :'> more. The anal fin must have been comparatively 

 small ; in the original of PI. XXI. fig. 5, there are the bases of 9 rays, with traces 

 of stout basal fulcra. 



Horizon and Locality. — Middle Purbeck Beds : Swanage, Dorset. 



o. Pholidophorus purbeckensis, Davies. Plate XXII, figs. 1 — 3. 



1887. Pholidophorus purbeckensis, W. Davies, Geol. Mag. [3], vol. iv, p. 337, pi. x, figs. 2 — 4. 



1888. Pltolidoji/mriis purbeckensis, W. Davies, in R. Damon, Geol. Weymouth, ed. 3, Suppl. pi. xix, 

 fig. 1. 



1895. Pholidophorus jmrbeckensis, A. S. Woodward, Catal. Foss. Fishes, Brit. Mus., pt. iii, p. 460. 



Type. — Imperfect fish ; British Museum. 



Specific Characters. — Attaining a length of 8—10 cm. Length of head with 

 opercular apparatus about equal to the maximum depth of the trunk and nearly 

 one-quarter of the total length of the fish. Head and opercular bones smooth or 

 feebly rugose ; teeth stout and sometimes slightly recurved. Fulcra smooth, 

 unusually large and stout on all the fins. Pelvic fins inserted about midway 

 between the pectoral and anal fins ; dorsal fin opposed to the space between the 

 pelvic and anal fins, with about 10 rays, the length of the foremost and longest 

 somewhat less than the depth of the trunk at its insertion ; anal fin also with about 

 10 rays, as elevated as the dorsal; length from insertion of anal fin to that of 

 caudal fin about equal to maximum depth of trunk. Scales large and smooth, the 

 hinder margin not serrated ; those of the lateral line much deepened, some four 

 times as deep as broad ; two scales above and below those of the lateral line also 

 moderately deepened ; lateral line forming only a feeble ridge. 



Description of Specimens. — The type specimen (PI. XXII, fig. 1), obtained by 

 Mr. Robert Damon from the Lower Purbeck of the Isle of Portland, lacks the 

 greater part of the head, but displays well the contour of the trunk in side-view, 

 with fragments of all the fins. It also shows satisfactorily the squamation. 

 Another specimen, much splintered by crushing, also figured by Davies (loc. cit. 

 1887, pi. x, tig. 2), gives the proportions of the head and caudal fin, and displays 

 the characteristic large fulcra on the dorsal fin. A still finer specimen, with all 

 the fins, is represented somewhat magnified in PI. XXII, fig. 2, with a further 

 <'ii large rnent of the fin-fulcra in fig. 2a. A dwarf example evidently of the same 

 from a corresponding horizon at Teffont, Wiltshire, is shown enlarged twice 

 in PI. XXII, fig. 3. 



shown in a specimen figured by Davies (1887, pi. x, fig. 2), and in another 

 Swanage (B.M. no. P. L2347), the postorbital part of the cranial roof is very 



