Length of mandible (imperfect) 2.1 cm. Length of maxilla 2 cm. Length of rib 1 cm. Length of humerus 2 cm. Length of femur 2.4 cm. Length of radius and ulna 1 cm. Length of toe in foot 7 mm. 8 teeth in 5 mm. CHAPTER XIV. THE MICROSAURIAN FAMILY TUDITANIDÆ, FROM THE COAL MEASURES OF OHIO AND PENNSYLVANIA. =Family TUDITANIDÆ Cope, 1875.= Cope, Geol. Surv. Ohio, II, pt. II, p. 357, 1875. Lizard-like microsaurians; cranial elements strongly sculptured with pits or grooves or almost smooth, with weak punctulations. Orbits usually well forward; squamosal sometimes excluded from the parietal; skull hornless; teeth pleurodont, conical and sharp, smooth or slightly plicate; clavicle of a triangular shape, which is characteristic of all the species; vertebræ well developed and phyllospondylous, the osseous portion being merely a hollow cylinder, hour-glass-shaped; ribs curved, long, attenuated and intercentral; digits clawed; ventral armature absent in all but a single species and the association of the species is doubtful; tail moderate in length. Three genera with 13 species included in the family. These species are: _Tuditanus punctulatus_ Cope, Linton, Ohio. _brevirostris_ Cope, Linton, Ohio. _longipes_ Cope, Linton, Ohio. _minimus_ Moodie, Cannelton, Pennsylvania. _walcotti_ Moodie, Linton, Ohio. _Erpetosaurus radiatus_ Cope, Linton, Ohio. _obtusus_ Cope, Linton, Ohio. _tabulatus_ Cope, Linton, Ohio. _minutus_ Moodie, Cannelton, Pennsylvania. _sculptilis_ Moodie, Cannelton, Pennsylvania. _acutirostris_ Moodie, Linton, Ohio. _tuberculatus_ Moodie, Linton, Ohio. _Odonterpeton triangularis_ Moodie, Linton, Ohio. The association of these species in the one family is provisional and will need revision on the acquisition of new and more complete material. =Genus TUDITANUS Cope, 1874.= Cope, Trans. Amer. Phil. Soc., XV, p. 271, 1874. Cope, Geol. Surv. Ohio, II, pt. II, pp. 391, 1875. Type: _Tuditanus punctulatus_ Cope. The genus as here defined is a somewhat composite group and it is quite probable that some of the species here included will have to be removed to another genus when the anatomy of the forms is better known. The species of the genus are all moderately small, the largest barely attaining a length of 8 inches.