In the McAdams collection, an account of which will be given on page 339, is a fragment of an incisor of a horse. It has on it McAdams’s No. 25. It is doubtful that this tooth was found in the loess. All the fossils of that collection purporting to have been found in the loess are very white, while this is of a brownish color, and there is a coat of iron oxide adhering to some parts of it. This may or may not be the tooth mentioned by McAdams as above reported. 3. _Greene County._—At the meeting of the St. Louis Academy of Science just referred to, Mr. McAdams stated that teeth of an extinct horse had been brought up from the bottom of a well being dug in Greene County. More exact situation and the depth of the well were not mentioned. Both Greene and Madison counties are occupied by the Illinoian drift-sheet. The horse-teeth found in these counties might have come from Sangamon deposits; or possibly the Illinoian drift had been passed through and Yarmouth interglacial had been entered. The geologists J. A. Udden and E. W. Shaw (Belleville-Breese Folio, No. 195, U. S. Geol. Surv., p. 7) have noted in those quadrangles deposits which may consist of pre-Illinoian till; also old black soils which may belong to the Yarmouth. The quadrangles mentioned lie along the southern border of Madison County. The old soils were found at depths varying from 30 to 75 feet. In this region, too, the Illinoian drift is overlain by a blanket of loess. To arrive at any valuable conclusion, one ought to know just where specimens are found and at what depths and in what kind of deposits. On the other hand, the information is of the most meager kind. The specimens mentioned are not in a collection made by McAdams and now in the National Museum. MARYLAND AND DISTRICT OF COLUMBIA. (Map 17.) 1. _Marshall Hall, Charles County._—In the U. S. National Museum is an upper right molar, first or second, of a horse labeled as found at this place. It is credited to Mr. O. N. Bryan, who, some years ago, contributed many articles to the museum. The conditions of discovery are not known. The length of the grinding-surface is 28 mm., the width 27 mm. It probably belongs to _Equus leidyi_. According to Shattuck’s map of the Pliocene and Pleistocene of Maryland (Maryland Geol. Surv., 1906, plate I) this locality is occupied by Talbot deposits. Shattuck regards the Talbot as belonging to late Pleistocene times. The present writer does not accept this view.