[Illustration: Fig. 21. A. Outline drawing of type of _Tuditanus walcotti_ Moodie, from the Coal Measures of Linton, Ohio, showing impression of body and muscle at _M_. × 25. _cl_, clavicle; _fr_, frontal; _f_, femur; _h_, humerus; _nos_, nostril; _or_, orbit; _par_, parietal; _rb_, rib; _pp_, postparietal; _v_, vertebra; _pfo_, pineal foramen. B. Left leg of second specimen of Tuditanus walcotti. × 3.] The specimen includes, besides the body impression, the complete skull, a right clavicle, with portions of the left, a left humerus, 12 cervical and dorsal vertebræ, 10 pairs of ribs somewhat disturbed as to position, and a portion of the mandible. There are no traces of ventral scutellæ nor body scales in the smooth impression of the carbonized skin. One would expect to find impressions of the ventral scutæ in this specimen if they were present. Cope remarked on the apparent absence of scutellæ from members of the genus _Tuditanus_ as they were known to him, and no contrary evidence has since been brought to light. Until such evidence is forthcoming the absence of scutes will be taken as one of the generic characters of the genus _Tuditanus_. Under a magnification of 50 diameters the carbonized skin shows as folds and wrinkles, like muscle fibers, in some places; in others no traces of the muscular structure can be detected. The wrinkles may be impressions of the internal musculature of the body-wall of the abdomen. It is especially well preserved in the pelvic and pygal regions. Sections of the coal were made, but nothing definite could be determined as to the character of the impressions, as they were too poorly preserved and the coal was too soft to bear much handling. The specimen is preserved on the belly, with the dorsum of the skull uppermost. It has been practically impossible to determine the arrangement of any of the cranial elements except the f rentals, parietals, and postparietals, which have the relations indicated in figure 21, A. A median suture is clearly evident, with the pineal foramen well back in this suture. The bones of the skull are marked with faint radiating lines. It is in the form of the skull and the position of the orbits that the specific characters are found, as follows: the backward position of the eyes and the oval, pointed shape of the skull. The species is closely related to _Tuditanus minimus_ Moodie, from the Cannelton slates of Pennsylvania, and serves further to connect the forms from the Ohio and Pennsylvania localities. It differs from the last-named species in the position and form of the orbits, these structures being more oval in the present form and placed further back. The shape of the skull differs also in the almost entire absence of the posterior table. The median points of the orbits occupy the line which bisects the skull, and the interorbital width is less than the width of the orbit. The mandible is heavy and appears to have borne sharp, pleurodont teeth.