The mandible is similar in structure to that of the labyrinthodonts, with the elements marked by radiate flutings. I can detect no evidences of a lateral-line canal, such as is clearly marked in _Macrerpeton huxleyi_ Cope by a series of rounded pits, occupying the usual position of the operculo-mandibular lateral-line canal The teeth, of which 6 are preserved, are minutely striate, with smooth apices. They are dissimilar in size, showing a variation of 2 or 3 mm. in length. The sculpture is a coarse fluting, with no indications of the sharply marked pits of _Macrerpeton huxleyi_ Cope. The fragment of a skull preserved shows characters of the sculpture which are identical with those of the mandible. The bones are so crushed that it is impossible to tell the limits of the elements. I believe a portion of one orbit is represented on one corner of the block. The cranium appears to have been broad, and the fragment preserved, which is only about one-sixth of the skull, is larger than the entire cranium and mandibles of _Macrerpeton huxleyi_. The specific distinctness of the form can not be doubted, although it is a matter of regret that it is founded on so small a portion of the osteology of the animal. The species is proposed in honor of Dr. Bashford Dean, to whom I am greatly indebted for many kindnesses during the past 5 years in connection with my studies on Carboniferous Amphibia, particularly in the loan of the entire Newberry collection of Linton, Ohio, Amphibia. Measurements of the Type of Macrerpeton deani Moodie. mm. Length of portion preserved 115 Greatest width 50 Length of tooth 9 Width at base 4 Length of angular 95 Diameter of angular 25 Measurements of specimen No. 8535 G, American Museum of Natural History, associated with the above in the type description: Length of preserved portion 140 Diameter of orbit 22 =Family ANTHRACOSAURIDÆ Cope, 1875.= Cope, Bull. U. S. Nat. Mus., I, p. 10, 1875. Lydekker, R., 1890, Cat. Fossil Reptilia and Amphibia, p. 157.