BRITISH FOSSILS. 



3 



Plate VII. Fig. 2. 



PLEUROPHOLIS CR ASSIC AUDUS. Sp. Nov. 



The specimen figured on the same plate with the above, No. 2, was 

 found some years ago by Mr. W. Brodie in the bed known in the 

 Durdlestone Bay section as the Insect Bed. It is now the property 

 of the Eev. P. B. Brodie, of Rowington. It agrees with the genus 

 FleuTopliolis in the large size of the lateral scales, and in the 

 extent and position of the anal fin ; but differs from the species last 

 described in the more massive proportions of the hinder part of 

 the body, and in the characters of the caudal fin. The specimen 

 measures one inch and three quarters from the nose to the base of 

 the tail, and is three-tenths of an inch in depth. The latter mea- 

 surement falls short of the actual dimensions of the fish, as the 

 dorsal and ventral portions are wanting, and the larger scales alone 

 remain. The head agrees for the most part with that of Pleuro- 

 pholis attenuatus. The operculum is, perhaps, relatively larger, 

 and the ganoid external layer thicker, characters which are re- 

 peated in the squamation. The scales comprised in the principal 

 series are broader, thicker, and straighter, those in the vicinity of 

 the tail are longer and more irregular in form. The position of the 

 anal fin is discernible, but its characters are indistinct. The 

 caudal fin has some strong fulcral scales on its lower margin, and 

 appears to have been much stronger and less furcate than in the 

 other species. A small fish discovered by the late Count Miinster 

 in the quarries of lithographic stone at Kelheim has a very close 

 resemblance to this species, but the scales are more delicate and 

 •greatly more numerous. The tail is more like that organ in 

 Pleuropholis attenuatus. A figure of this species is given on 

 the Plate, No. 3. Professor Agassiz originally named it Pholido- 

 phoTUs Icevissimus ; he subsequently removed it to his new genus 

 Nothosomus ;* but it must now be considered a Pleuropholis, 



Locality. — Pleuropholis crassicaudus is from the Insect bed of the 

 Purbeck strata in Durdlestone Bay, No. 106 of Mr. Austen's table.f 



Plate VII. Fig. 4. 



PLEUROPHOLIS LONGICAUDUS. Sp. Nov. 



When engaged in examining materials for describing the several 

 species of fossil fishes from the Purbeck strata published in the 

 Eighth Decade of the Memoirs of the Geological Survey, I found 



! * Poiss. Foss., vol. 2, p. 288. 



t Guide to the Geology of the Isle of Purbeck, by the Eev. J. H. Austen, page 17. 



