T. Stock — Keuper Conglomerate, Bristol. 213 



slender, and must have been terminated at each extremity by unos- 

 sified cartilage. The tibia (? or fibula) also appears to have been 

 slender, equalling about one-half the length of the femur ; but its 

 outline is not satisfactorily shown. 



The dermal scutes cover the whole of the trunk so far as preserved, 

 all being oval in shape, deeply imbricating, and exhibiting promi- 

 nent concentric lines of growth. Those of the ventral armour (Fig. 

 1, V.) are much lai'ger than those of the dorsal {d.); and the former, 

 when magnified (i>^),show feeble radiating lines either superficial or 

 structural. 



The fossil thus described may be assigned w^ithout much doubt to 

 the Microsaurian family of Hylonoraidse as restricted by Fritsch.^ 

 So far as known, indeed, it cannot be separated from the type genus 

 Hylonomus itself. The general proportions are similar, and there 

 are the same indications of the laterally compressed form of the 

 trunk; w^hile the relative stoutness of the anterior ribs will also 

 doubtless be proved to characterize the typical species from Nova 

 Scotia when sufficiently well preserved examples are discovered.^ 

 The closely allied genus Hyloplesion of Fritsch^ is distinguished by its 

 short interclavicle with a long posterior process, by its more slender 

 anterior ribs, and by the relatively smaller size of the ilium ; and 

 the remaining genera are excluded from comparison by equally 

 obvious characters. Upon present evidence it is thus proposed to 

 regard the Microsaurian from the Lancashire Coal-Measures as a 

 species of Hylonomus ; and as this appears to be new, it may appro- 

 priately bear the name of H. WUdi, in honour of its discoverer, Mr. 

 George Wild, whose long-continued researches in the Burnley Coal- 

 field, especially in connection with the Carboniferous Flora, are well 

 known. Among distinctive specific characters may be enumerated 

 the form and proportions of the mandible and dermal armour ; while 

 the precise contour, size, and ornament of the interclavicle will not 

 improbably prove to be of diagnostic value when this element is dis- 

 covered in the several species from Nova Scotia. 



YII. — Observations on a Keuper Conglomerate and on a Breccia, 



BOTH Recently Exposed in the Neighbourhood of Bristol. 



By T. Stock, Esq. 



1. A conglomerate in the Keuper. — Whilst a drain was being cut in 



Argyle Street, joining Upper and Lower Eastvilles, one of the upper 



beds exposed consisted of a rather fine conglomerate, made up largely 



of rolled quartz pebbles of small size, compacted with rounded 



quartz sand and intermixed with coloured fragments (generally 



very small flakes) of softer shale or clays. I did not measure the 



thickness very carefully, but I should think that it did not exceed 



^ A. Fritsch, Fauna der Gaskohle, vol. i. p. 159. 



2 Sir J. W. Dawson, Geol. Mag. [3] Vol. VIII. p. 152. 



^ A. Fritsch, torn. cit. p. 160. Hyloplesion is considered to be identical witli 

 Hylonomus by Credner (Zeitscbr. deutscb. geol. Ges. vol. xxxvii. p. 734) ; but tbis 

 identification is very doubtful, as lately remarked by Sir J. William Dawson (Geol. 

 Mag. [3] Vol. Vlll. p. 163). 



