2 



BRITISH FOSSILS. 



two succeeding ones are nearly as long, but tlie diminution in length 

 of the remainder is very rapid. They are all strong, and maintain 

 their size with little variation up to the point where they bifurcate. 

 The transverse sutures are distant, the larger rays having not more 

 than five or six, so long as they continue single. The ventral fins 

 are deficient in the specimen. The anal fin is dislocated, but seems 

 to have been nearly co-extensive with the dorsal fin. The rays are 

 shorter, and the diminution in length of the distal ones more 

 abrupt. The upper lobe of the tail is remarkably long and at- 

 tenuated, and is invested with small scales to its extremity. The 

 most distinctive character of the species is found in the scales. 

 These are large and solid, of rliomboidal form, and covered with 

 strongly-defined irregular ridges and furrows, the former termi- 

 nating in sharp cusps on the posterior or free margins The anterior 

 part of the scale, where it is overlapped by the antecedent scale, is 

 marked with two or more elevated lines parallel to the outline of 

 the border of the scale, being probably lines of increment. These 

 peculiarities are very clearly and faithfully delineated in the mag- 

 nified view of the scale given in the accompanying plate. 



Affinities. — Fcdwoniscus Fgertoni is most nearly allied to the 

 species found at Burdie-house, and especially to Pcdceoniscus 

 Rohisoni.^ It is, however, easily distinguished from this species 

 by the smaller size of the head, the greater depth of the trunk, and 

 the rugous character of the scales. Falceonisciis monensis'\ has not 

 yet been found entire ; there is nevertheless sufiicient evidence in 

 the detached scales to distinguish it from tliis species. The orna- 

 ment of the surface is less prominent, and the lines are parallel to 

 each other, and straight, whereas in Pcdceoniscus Egertoni they are 

 irregular and sinuous. No foreign species has the least resemblance 

 to it. 



History. — In 183 5, J I communicated to the Geological Society of 

 London the discovery of numerous remains of fishes in the coal 

 shale of the Silverdale pits near Newcastle-under-Lyne. They con- 

 sisted of bones and scales belonging to the genus M egalichthys, then 

 recently found by the late Dr. Hibbert Ware, at Burdie-house, and 

 figured in the Transactions of the Koyal Society of Edinburgh, § teeth 

 of Diplodus gihhosus, and scales of a small Pcdceoniscus, which 

 were pronounced by Professor Agassiz to indicate a new species of 

 the genus. Shortly afterwards, my brother, the Rev. W. Egerton, 

 discovered in the same bed the pretty little specimen represented in 



* Agassiz, Fois. Foss., vol. ii. p. 88. f Quart. Jour. Geol. Soc, 1849, vol. vi. p. 5. 

 % Proc. Geol. Soc, 1835. § Vol. xiii. pi. 8 and 11. 



