A HISTORY OF LEICESTERSHIRE 



acutus" of the Lias of Dorset and Yorkshire. This specimen was discovered 

 in 1 874. It should be mentioned that Leicestershire is not given as one of 

 the localities of this species by Dr. Smith Woodward. 13 To this same family 

 (in which scales are usually wanting) undoubtedly belongs a small imperfect 

 fish from Barrow in the Leicester Museum which has been made the type of 

 a genus and species under the name of Browneicbtbys ornatus, the somewhat 

 unclassical generic title having been bestowed in honour of Mr. M. Browne, 

 while the specific name refers to the enamelled plates investing the head. 

 Dr. Woodward 14 believes this fish to be related to Belonorhynchus and Saurich- 

 thys, from both of which it differs by the presence of scales on the fore part 

 of the body. At present this singular fish is known only by the type 

 specimen. A third family of Chondrostei the typical Chondrosteidae is 

 represented in the Barrow Lias by Chondrosteus acipenseroides, a large sturgeon- 

 like fish measuring about a yard in length. The Barrow specimen 16 is 

 preserved in the Leicester Town Museum. 



Turning to ganoids, or enamel-scaled fan-finned fishes of another group 

 (Protospondyli), we find in the family Semionotidae the species Dapedius dor sails 

 fairly common in the Barrow Lias, from which formation the British 

 Museum possesses a considerable number of specimens. Dapedius, it may be 

 observed, is one of the deep-bodied group of ganoids, and is represented by 

 many species from the Mesozoic formations. Some of the specimens now 

 assigned to D. dorsalis were at one time regarded as indicating distinct species, 

 under the names of D. (Tetragonolepis) monilifer and D. stn'o/atus, one half of 

 a split nodule from Barrow containing one of these fishes in the British 

 Museum being labelled in the handwriting of the great ichthyologist Agassiz 

 with the former name, while the opposite half bears the latter designation. 1 ' 

 There is, however, a second well-defined species of the genus from Barrow, 

 characterized by its remarkably rounded outline, and hence named D. orbis. 

 At present it is unknown from any other county. Specimens are preserved 

 in the British, Dublin, Leicester, Derby, and Warwick Museums. A fish 

 from Barrow in the British Museum typifies a species of the genus Mesodon, 

 which belongs to another family of the same group of ganoids, known as the 

 Pycnodontidae, and taking its name from the numerous button-like teeth on 

 the vomer and the opposing portion of the lower jaw. The Leicester 

 species, Mesodon liassicus, is common to the Lower Lias of Somerset and 

 Gloucestershire. Yet another family the Eugnathidae of this group of 

 ganoids has several representatives in the Barrow Lias. The first of these is 

 Eugnathus bastingsiae, a species belonging to a genus numerously represented 

 during the Mesozoic epoch ; this particular species was first described from 

 Barrow, although it has been subsequently recorded from the Warwickshire 

 Lias. On the other hand, the second Leicestershire member of the family 

 appears to be at present unrecorded from any other locality but Barrow. It 

 is mentioned in Mr. Browne's volume as Pholidophorus bastingsiae, but its 

 proper title is Heterolepidotus serrulatus, although it has been confounded with 

 another member of the same family bearing the name Eugnathus serrulatus. 

 The genus Heterolepidotus includes several other species from the Mesozoic 

 formations. Of the Barrow species the British Museum possesses a consider- 



" Browne, op. cit. 197. ' Op. cit. iii, 21. M Op. cit. iii, 23. 



See Browne in Trans. Leic. Lit. and Phil. Soc. 1889, p. 16. M Woodward, op. cit. 139. 



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