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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. 24