96 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



of the form will be attempted. The sculpturing on the parietals is, however, dis- 

 tinct enough to show relationship with the previously described specimen, and the 

 form of the body impression, the absence of abdominal scutes, the shape of the clavi- 

 cle and its sculpture, and the proportions of the hind limbs all agree with the charac- 

 ters which have been assigned to the genus Tuditanus. The fragment of the jaw is 

 interesting as giving the first information as to the character of the mandible in the 

 genus Tuditanus. It is very slender and of uniform width as far as preserved. The 

 teeth are short, blunt cones, apparently pleurodont. 



The clavicle is of the typical Tuditanus form, with the sculpturing lines radiating 

 out from the angle. The impression of the body adds nothing to that already 

 described for the type specimen. The nearly entire hind limb is of great interest as 

 adding another example of the phalangeal formula. The foot is almost perfectly 

 preserved, and the formula was probably 2-2-3-3-2. The endochondrium of the 

 limb bones is not highly developed. About a dozen vertebrae are represented by 

 molds in the soft coal, but nothing of their structure can be determined. 



The sharp, reptile-like claws in which the toes end (fig. 2 1 , B) recall those of Eosau- 

 ravus and of Tuditanus minimus Moodie. It is another link in the chain of the 

 suggested relationship between the microsaurians and the early reptiles. 



Measurements of the Second Specimen of Tuditanus walcotti Moodie. 



mm. mm. 



Length of entire body impression 75 Length of clavicle 8 



Width across belly, maximum 16 Width of clavicle, maximum 4 



Length of skull ?I7 Length of hind limb 22 



Posterior width of skull ?I4 Length of femur 8 



Length of fragment of jaw 4 Length of tibia (?) 6 



Width of fragment of jaw i .5 Length of metatarsal 2 



Length of tooth in jaw 25 Length of first digit 6 



Genus ERPETOSAURUS Moodie, 1909. 



Moodie, Bull. Amer. Mus. Nat. Hist., xxvi, p. 348, fig. i, 1909. 

 Moodie, Proc. U. S. Nat. Mus., 37, p. 21, 1909. 



Type: Erpetosaurus radiatus Cope. 



Skull stout, elements sculptured with radiating grooves, ridges, and pits ; orbits 

 large and usually placed far forward ; occiput sometimes with posterior table ; skull 

 more or less rounded ; lateral-line canals consisting of supraorbital, suborbital, jugal, 

 and temporal canals, the last two uniting to form a circular canal in one species; 

 clavicle triangular, sculptured like the skull. 



Our knowledge of the genus is confined to the skull. The genus was established 

 for certain members of the genus Tuditanus and other forms which have been re- 

 cently described. The species of the genus are: E. radiatus Cope type, E. tabulatus 

 Cope, E. tuberculatus Moodie, E. obtusus Cope, E. minutus Moodie, E. acutirostris 

 Moodie, E. sculptilis Moodie. All of the species are from the Linton, Ohio, Coal 

 Meastu-es, with the exception of E. sculptilis and E. minutus, which are from the 

 Cannelton, Pennsylvania, slates. 



The position of the genus as to family is a little uncertain, since family charac- 

 ters are not yet well understood among the Carboniferous forms on account of the 

 lack of information as to the structure of the animals. If we take the absence of 



