mm. Length of animal, as preserved 18 Length of skull 6.5 Posterior width of skull 5.5 Length of side of skull 6.5 Diameter of orbit 65 Interorbital width 2 Length of tooth 0.25 Length of vertebra 1.45 Width of vertebra 35 Length of humerus 2.25 Distal width of humerus 35 CHAPTER XV. THE MICROSAURIAN FAMILY STEGOPIDÆ, FROM THE COAL MEASURES OF OHIO. =Family STEGOPIDÆ Moodie, 1909.= Moodie, Jour. Geol., XVII, No. 1, 79, 1909. The chief family characters are the large lacrimal, unknown in other species of Coal Measures Amphibia, the central position of the orbits, the general form of the skull, and the peculiar, short, divaricate horns from the squamosal. If an intertemporal element is present in the skull, which is suggested as a possibility, the family is further distinct. The type species is Stegops divaricata Cope from the Linton, Ohio, Coal Measures. The group seems to be distinct and has no immediate allies, being confined to the American Coal Measures. =Genus STEGOPS Moodie, 1909.= Moodie, Jour. Geol., XVII, 79, 1909. Type: _Stegops divaricata_ Cope. This genus has been erected for the reception of the peculiar form described by Cope as _Ceraterpeton divaricatum_, but there are good reasons why the form can not be retained in the genus. The position of the orbits in Stegops (plate 25, fig. 3) is different from _Ceraterpeton_ and the muzzle is rounded, not truncate as in the latter form. The horns are of a different type and there is no indication of the tabulare protuberance which is present in _Ceraterpeton_. The sculpturing of the cranial elements is also distinctive in the present form, consisting of radiating grooves and ridges; the cranium of _Ceraterpeton_ appears to be but slightly sculptured. There is no lateral projection from the border of the skull in Stegops, as there is in the other genus. The structure of the skull of _Ceraterpeton_ is practically unknown, except in a very general way, although Andrews (8) was able to make out some of the elements and to trace the lateral-line canals. A structural comparison is thus impossible, but on the basis of form alone there are good generic distinctions. The present genus is apparently distinct from other genera in the presence of an intertemporal, but additional material will be required before a satisfactory determination is possible. The genus _Diceratosaurus_ of Jaekel (347) is distinct in the arrangement of the elements of the cranium, the general form of the skull, and in the two known species of _Diceratosaurus_ the orbits are located well anteriorly, but in Stegops they are in the median transverse line of the cranium. The genus _Stegops_ is distinct from _Eoserpeton_ in the smaller size of the prosquamosal,