98 PROCEEDINGS OF THE ACADEMY OP 



Another molar is from St. Mark's River, Florida. It is an inferior one, and 

 of the coarse plated variety. The grinding surface is irregular or terraced, 

 eight and a half inches long, four inches wide; and it includes eleven lobes 

 or double plates. Five additional unworn lobes succeed. The breadth of the 

 tooth is ten- and one-half inches ; its depth to the root, eight inches. 



Taking advantage of my proximity, I went to Amherst, and spent a couple 

 of hours with Prof. C. N. Shepard in examining the Museum of Amherst 

 College. 



Prof. Shepard has recently collected together many interesting fossil remains 

 of vertebrata. Among these are a multitude of specimens obtained by his 

 son from St. Helena Island, and the famous Ashley River deposits of South 

 Carolina. Those from the latter locality consist mainly of Zeuglodonts, Ceta- 

 ceans and Fishes, but also include remains of Mastodon, the Elephant, and of 

 Equus major and E. fraternus. The St. Helena Island fossils consist of bones, 

 fragments of jaws and teeth of the Mastodon. Among them were noticed two 

 inferior tusks, which measured about ten inches in length and two inches in 

 diameter at the base. 



The same collection contained a large molar of the American Elephant, of 

 the coarse plated variety, from California. Some remains of Mastodon from 

 the latter place struck me from their peculiarity, and these Prof. Shepard was 

 so kind as to loan to me for examination and description. 



One of the specimens, which lies on the table, is the fragment of a tusk 

 from " Dry Creek," "Stanislaus Co., California. It indicates a species totally 

 differeut from the American Mastodon, and in its peculiarities exhibits a re- 

 lationship with the Mastodon angustidens of the middle tertiary period of Eu- 

 rope. The fragment is six inches in length, is slightly curved in two direc- 

 tions, and in transverse section is ovate with the anterior pole acute. The 

 pulp cavity, opening half the diameter at the broken base of the specimen, 

 extends about half its length to the end. The convex side of the tusk pos- 

 sesses, as in Mastodo?i angustidens, a broad band of enamel, which reaches from 

 the acute edge more than two-thirds the depth of the surface. The enamel is 

 somewhat rugose and is two-thirds of a line thick. At one spot, towards the 

 smaller end of the fragment, it has been irregularly worn through for the ex- 

 tent of about an inch and a half. The opposite side of the specimen, from 

 the acute edge, has been worn off to an extent about equal to two-fifths of the 

 surface. The broken ends of the fragment exhibit very conspicuously the 

 beautiful arrangement of decussating curved lines so characteristic of the 

 ivory in the tusks of the great proboscidians. 



The vertical diameter of the base of the fragment is 28 lines, the transverse 

 diameter 19 lines ; the vertical diameter at the opposite end is 22 lines, the 

 transverse diameter 16 lines. The entire length of the tusk appears to have 

 been less than two feet. 



The question arises as to what species the tusk fragment shall be attributed. 

 It certainly does not belong to the common American Mastodon, nor is it pro- 

 bable that it belonged to the pliocene Mastodon mirificus. May it probably per- 

 tain to the hardly known Mastodon obscurus ? In the present uncertainty I Mould 

 look on the specimen as characteristic of a peculiar species, allied to the M. 

 angustidens of Europe. For the name of the species I would propose that of 

 Mastodon Shepardi, in honor of Prof. C. N. Shepard, whose name has so long- 

 been identified with the interests of natural history. 



The second specimen, exhibited to the members, consists of a fragment of a 

 lower jaw containing the last molar tooth, and was discovered in Contra Costa 

 county, California. No information in regard to the age of the deposit, or 

 the character of the locality in which the fossil was found, accompanies it. 

 The bone is friable, and measures, below the position of the tooth, five and a 

 half inches in depth. Attached to the fossil there is a portion of soft gray 

 rock, part of the matrix in which it has been imbedded. The tooth is per- 

 fect and well preserved. It has the same general form and constitution as 



[Sept. 



