THE MICROSAURIAN FAMILY TUDITANID^. 95 



Moodie, from the Cannelton slates of Pennsylvania, and serves further to connect 

 the forms from the Ohio and Pennsylvania localities. It differs from the last-named 

 species in the position and form of the orbits, these structures being more oval in the 

 present form and placed further back. The shape of the skull dififers also in the 

 almost entire absence of the posterior table. The median points of the orbits occupy 

 the line which bisects the skull, and the interorbital width is less than the width of the 

 orbit. The mandible is heavy and appears to have borne sharp, pleurodont teeth. 



The vertebral column is represented by little more than a mold of the form of 

 the vertebrae, so that little can be said of its character. The individual vertebrae are 

 short and hour-glass-shaped. The ribs are borne intercentrally, as in all the micro- 

 saurians which have been studied from the Linton deposits. The ribs are rather 

 long and somewhat heavy, slightly curved and expanded at the proximal end, as 

 though an incipient bicipital condition were present. 



The right clavicle, which is preserved as an impression, is entire. Its impres- 

 sion shows this element to have been ornamented on its ventral surface with radi- 

 ating grooves and ridges which started at the lower angle of the bone. The element 

 is distinctly triangular, which is characteristic of the genus Tuditanus, so far 

 as known. The fragment of the left clavicle adds nothing to our knowledge of 

 the element. 



The left humerus recalls in a striking way that of Tuditanus longipes Cope, and 

 it was once entertained as a possibility that the present form might be a member of 

 that species, since the skull is lacking in T. longipes. Sufficient specific differences 

 were found, however, in the ribs, which, in T. longipes, are very long, slightly curved, 

 and delicate, but which, in the present form, are comparatively heavy. Other char- 

 acters sufficiently diagnostic are fotmd in the form assumed by the vertebrae in the 

 two forms. 



Measurements of the Type of Tuditanus walcotti Moodie. 



mm. mm. 



Length of specimen 70 Length of vertebral column, as preserved 50 



Length of skull 20 Length of a vertebra i .75 



Posterior width of skull 14 Width of a vertebra 50 



Width of skull, anterior to orbits 10 Width of body impression 15 



Length of orbit 4 Length of humerus 6 



Width of orbit 2 Median width of humerus 50 



Interorbital width 3 Width at end of humerus 2 



Length of clavicle 9 Length of rib 8 



Greatest width of clavicle 4 Width of rib 25 



The above-described specimen was collected by Mr. R. D. Lacoe, of Pittston, 

 Pennsylvania, from Linton, Ohio. 



A second individual (No. 4481, U. S. National Museum) of this species is indi- 

 cated by a rather poorly preserved specimen on a slab of soft coal from the Linton 

 mines. The following portions of the animal have been detected and will be dis- 

 cussed: partial impression of the skull, with a fragment of a minute jaw, in which 

 are minute teeth ; right clavicle ; part of the impression of the body ; nearly entire 

 left hind limb; impressions of about a dozen vertebras, very indistinct. 



The impression of the skull is distinct only in a favorable light, and even then the 

 boundaries of the cranium are a little uncertain. For this reason no representation 



iti 



