116 JDr. R. H. Traqiiair — On the Genus Megaliehihys. 



Egerton, who, in Morris's " Catalogue of British Fossils," proposed 

 its reference to the family of " Sauroidei-dipterini " (Sauroidei- 

 dipteriens) instituted by Agassiz for Dipterus and the genera just 

 mentioned. From this group, however, M'Coy very properly struck 

 out Dipterus,^ which from its rounded scales he classed as a 

 " Coelacanth," and which we now know is in fact a Dipnoan, allied 

 to Ceratodus. The probable position of MegalichtJiys in the " Sauro- 

 dipterini " was also indicated by Pander, who mentioned its close 

 relationship to Osteolepis in the arrangement of its head-bones, the 

 shape of its scales and teeth, and, above all, in the microscopic struc- 

 ture of its hard parts, though he also seemed to hesitate on account 

 of our want of knowledge of the conformation and position of its 

 fins.^ A similar opinion, coupled with a similar hesitation, is 

 expressed by Prof. Huxley in his well-known essay on the Classifi- 

 cation of the Devonian Fishes.^ 



Prof. Young, in a paper on " Carboniferous Glyptodipterines," * 

 makes some observations on MegalicJithys, including a statement that 

 "since 1861 specimens illustrating the form of the fins have been 

 acquired by the Museum (Jermyn St.) ; but the description and illus- 

 tration of these parts are reserved." I am not aware of any account 

 of these specimens having been yet published. An important point 

 is however his abolition of M 'Coy's genus Centrodus, as a mere 

 synonym of Megalichthys. Centrodus was founded upon a detached 

 tooth from the Coal-measures of Carluke, Lanarkshire. 



Mr. J. Ward, in a paper on the fishes of the North Staffordshire 

 Coal-field, classes Megalichthys in the family Saurodipterini, and states, 

 moreover, that in a specimen in his collection the pectoral fins are 

 well preserved; — "They are lobate, i.e. the central portion, of the 

 fin is covered with scales, the fin-rays forming a fringe round the 

 lobe." ' 



There can be no doubt that the position of Megalichthys is in the 

 family of Saurodipterini, as defined by Pander, and adopted by 

 Huxley and other writers. In every matter of "family " importance 

 its structure conforms closely to that of Osteolepis. 



The resemblance of the scales in external form is sufficiently 

 obvious to every one, and their close correspondence in microscopic 

 structure may be seen by comparing the figures of transverse sections 

 given by Williamson in Megalichthys,^ by Pander in Osteolepis.'^ 



As regards the osteology of the head, the resemblance is exceed- 

 ingly close between Megalichthys and the Old Eed Saurodipterines, as 

 is at once evident on comparing the figure of the head of Megal- 

 ichthys given by Agassiz with those of Osteolepis given by himself, 

 by Hugh Miller,* and by Pander. It is not within the scope of the 

 present paper to enter into a minute or even a general account of 



1 Britisli Pal. Foss. pp. 590-502. 



2 Die Saurodipterinen, &c., des devonischen Systems, p. 5. 



3 Dec. Geol. (Survey, x. 1861, p. 12 



i Quart. Journ. Geol. Soc. vol. xxii. 1866, pp. 596-608. 



« Nortli Staffordshire Nat. Field Club ; Addresses and Papers, Hanley, 1875, p. 228. 

 " Phil. Trans. 1849, pi. xlii. fig. 18. '' Saurodipterinen, etc., pi. v. fig. 8. 



8 Footprints of the Creator. 



