Sellards — Cfilamytheriwn septentrionalis. 139 



Art. 1LII.— Chlamytherium septentrioiialis, an Edentate 

 from the Pleistocene of Florida ; by E. H. Sellards. 



The genus Chlamytherium^ of which C. humboldtii is the 

 type species, was established by Lund in 1838 on material from 

 South America.* Distinctive characters of the genus are 

 found in the molar teeth, Avhich are elongated from front to 

 back, the larger teeth being as much as three or four times as long- 

 as broad. On the exterior of the molar teeth is a broad furrow 

 which partially divides the crown into an anterior and a 

 posterior pillar. On the inner surface of the tooth is seen two 

 or three faint furrows, which, however, are but faintly seen on 

 the crown. The cross section of the molar is thus that of an 

 ellipse compressed at the center, more strongly so from the 

 outer side. Traversing the central line of the molar teeth from 

 front to back is a thin dark band which is in fact made up of 

 two bands of dark colored dentine placed in juxtaposition, 

 giving an appearance such as would result from the collapse of 

 a cavity the walls of which were lined by a dark band of 

 dentine. Moreover in breaking, the tooth parts along this 

 line, the bands of dentine are sometimes somewhat separated 

 from each other, and in this case, according to Ameghino, the 

 cavity between is filled with cement. Although seldom pre- 

 served in the fossils, the exterior of the tooth is said also to 

 have been covered with a layer of cement which is thickest in 

 the lateral furrows. At the base the tooth shows in the 

 fossil condition a large undivided cavity, which narrows 

 upward, becoming closed near the middle line of the tooth, 

 beyond which is the dark band already described. 



The lower jaw of Chlamytherium, is pointed in front and 

 contains nine teeth. Of the teeth the posterior six are 

 molariform in appearance and function, while the anterior 

 three are reduced and are more nearly circular in cross section. 

 In general appearance the jaw is distinctly glyptodont. 

 From the glyptodonts, however, the genus is distinguished not 

 only by the structure of the teeth, which lack the tripartite 

 division of the crown and base, but also by the fact that the 

 ascending ramus of the jaw is inclined gently backward, and 

 does not turn up at a right angle, or at more than a right 

 angle as in the glyptodonts. Moreover, the shield consists of 



* Overs, K. Danske Via. Selst, Forli., viii, p. Hi, 1838. 



In the original description the generic name was written Chlamytherium 

 although subsequently Lnud as well as others used the form Chlamydotherium. 

 In his Bibliography and Catalogue of Fossil Vertebrates (Bull. IT. S. 

 Geological Survey, No. 179, p. 581, 1901) Dr. O. P. Hay used the form 

 Chlamytherium. 



