John Samuel Budgett (79, p. 162), in his discussion of the "Structure of the Larval Polypterus," refers to the above-described specimen of "aistopodous Stegocephali," _i.e._, _Dolichosoma longissimum_ Fritsch, and calls especial attention to the similarity of the external rod of segmented cartilage on the hyomandibular of _Polypterus_ to this structure, to which Fritsch has assigned a branchiate nature in _Dolichosoma_. There is no doubt in the mind of the present writer, however, that the rod of cartilage, referred by Fritsch to the gills, can be other than scutellate rods of the ventral armature, these rods belonging to the armature of the breast or throat. The evidence for this conclusion is furnished by Fritsch himself (Fauna der Gaskohle, Bd. I, plate 18, fig. 11), where all may read in the figure of the specimen the facts of the case. There is quite evidently no justification for Fritsch's conclusion of the branchiate nature of _Dolichosoma_. There is no evidence of any gill-like structure in the American snake-like amphibians of the Coal Measures. Reviewing, then, the characters of the group which have been assigned by various observers, it will be seen that there is but a single character which holds good: "body long and snake-like." This is totally insufficient for the retention of the group. I therefore propose to abolish the group entirely from zoological classification. It is not even a family. It will, however, be convenient to refer to the snake-like forms as "aistopodous." CHAPTER XIII. THE MICROSAURIAN FAMILY HYLONOMIDÆ, FROM THE COAL MEASURES OF NOVA SCOTIA. =Family HYLONOMIDÆ Fritsch, 1883.= Fritsch, Fauna der Gaskohle und der Kalksteine der Permformations Böhmens, Bd. 1, p. 159, 1883. Lydekker, Cat. Fossil Reptilia and Amphibia, IV, p. 201, 1890. The following characterizations of the family are those given by Lydekker (393, p. 201) based on Fritsch (251): Body slender and lizard-like; skull narrow, with smooth or faintly sculptured bones; neural spines of vertebræ well developed, and long, slender ribs. Teeth smooth, or with grooved summits. The whole body covered with sculptured scutes. Internal gills may be developed. Fritsch (251, Bd. I, p. 159) gives the following in his original description: "Stegocephali von Baue schlanker Eidechsen mit schlanken langen Rippen. Wirbel amphicoel mit stark entwickelten oberen Dornfortsätzen. Schädelknochen glatt oder schwach verziert. Schuppen gross, verziert, den ganzen Körper deckend. Zähne glatt oder mit verzierte Spitze. Kiemenbogen bei einigen angedeutet. Mittlere Kehlbrustplatte unbekannt. Coracoidea ähnlich wie bei Branchiosaurus schlank, winkelig gebogen." Fritsch includes the following genera in the family: _Hylonomus_, _Hyloplesion_, _Smilerpeton_, _Seeleya_, _Orthocosta_, and _Ricnodon_. The family includes the following species: