BRITISH FOSSILS. 



5 



the pectoral fin. These fins are both small^ and the rays continue 

 the greatest part of their length without subdivision ; they are, 

 however, fimbriated at their extremities. The scales are very thick 

 and solid, and of variable and rather irregular forms. The ganoid 

 investment is very dense and lustrous. The posterior margins are 

 coarsely serrated. A large fulcral scale occupies the base of the 

 upper lobe of "che tail. The latter organ is mutilated, but it is 

 probable from what remains, that it v/as blunted in form, or at all 

 events not deeply forked. The lateral line is nearly horizontal. 

 The head figured as probably appertaining to this fish shows the 

 operculum and the lower jaw. The former is characterized by a 

 rough pattern of flattened tubercles of enamel, very difi*erent in 

 this respect, as also in form, from the corresponding part in the 

 genus Pholidophorus. The lower jaw is strong, and armed with a 

 single row of stout incurved teeth, in the form of elongated cones, 

 with rather blunt points, not unlike the outer row of teeth of some 

 of the more slender toothed Lepidoti or jEchmodi. They are well 

 seen in a detached jaw represented at fig. 11 of the plate. On 

 comparing this figure with the PJiolidophorus head (fig. 2.), the 

 difierence of the dentition of the two genera is easily appreciated. 



Locality. — This Ichthyolite was discovered by Edmund Thomas 

 Higgins, Esq., at Aust, in the same block of Gotham marble which 

 contained the two species of Pholidophorus figured on the same 

 plate. It is in his possession, and I am indebted to his liberality 

 for the opportunity afforded me of making it available for this 

 Decade. 



Explanation of Plate. 



rig. 1. Pholidophorus Higginsi, size of nature. 

 I'ig. 2. Head of ditto enlarged, twice the size of nature. 

 Eigs. 3. 4. 5. Scales of ditto, 4 times the size of nature. 

 Eig. G. Pholidophorus nitidus, twice the size of nature. 

 Eigs. 7. 8. Scales of ditto, 4 times the size of nature. 

 Fig, 9. Legnonotus Cothamensis, twice the size of nature. 

 Eig. 10. Head of ditto ditto ditto. 



Eig. 11. Lower jaw of ditto ditto ditto. 

 Eig. 12. Scale of ditto, 4 times the size of nature. 



P. DE M. Grey Egerton. 



July 7, 1853. 



