Baltimore Johns Hopkins press 1906 .
291 p. , The third volume of a series of reports dealing with systematic geology and paleontology of Maryland. | William Bullock Clark, state geologist. | Versos of several plates on which brief explanations are given are numbered as pages. 26 cm..

By Lucas, Frederic A..
New York City American Museum of Natural History 1950 .
20 p. , Man and nature publications. 20 cm..