THE AMPHIBIANS AND REPTILES OF MONA ISLAND, WEST INDIES BY KARL P. SCHMIDT In arranging the collection of reptiles in Field Museum of Natural History, I was much interested to find three specimens from Mona Island, one of the rare boa, Epicrates monensis, one of the Mona Island Dromicus, which I now believe to represent a well-marked new form, and one of the skink, Mabuya sloanii. These specimens were col-lected by Wilmot W. Brown, Jr., in February, 1892 while collecting birds on Mona Island for the late Charles B. Cory. They were presented to the Field Museum of Natural History by Mr. Cory, together with other West Indian collections. The birds collected at the same time formed the subject of a brief note by Mr. Cory (1892). In view of the interesting results of a careful examination of the West Indian burrowing snakes of the genus Typhlops, begun by myself in 1920, and elaborated by Miss Doris M. Cochran in 1924, the Mona Island snake of that genus offered a special problem for investigation. The Field Museum of Natural History is indebted to the Naturhistor-isches Museum in Hamburg for the loan of their two specimens of Typhlops from Mona Island (the only ones known), for study in this connection. These specimens form the types of a distinct species, and throw added light on the relations of the Mona Island fauna. The drawings for the present paper are the work of Mr. Carl F. Gronemann. GEOGRAPHY OF MONA ISLAND Mona Island 1 is situated in the Mona Passage, midway between Santo Domingo and Porto Rico, and in line with Saona Island (off the southeast corner of Santo Domingo) and the southwest corner of Porto Rico. It is a block of tertiary limestone about six and a half miles long and four in greatest width, angular in outline, and rising precipitously from the sea on three sides. On the fourth side, to the southwest, a terrace, several hundred yards in width and ten or twelve feet above sea level, intervenes between the water and the cliff. The sea cliff ranges 1 Mona Island was visited by the writer in 1919 in the course of field work for the "Survey of Porto Rico and the Virgin Islands" by the New York Academy of Sciences. 149
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