THE MICROSAURIAN FAMILY UROCORDYLID^. 123 



The heavy line on the left of the drawing (fig. 24, B) represents the outline of the 

 preserved portion. The skull, as restored, may be a little too long, and the shape of 

 the horns is conjectural. In the orbit there are preserved 2 misplaced teeth show- 

 ing longitudinal fluting. The longest tooth is about 3 mm. 



MEASUREMENTS OF THE TYPE SKULL OF DICERATOSAURUS ROBUSTUS MOODIE. 



mm. mm. 



Median length of skull, estimated 67 Length of longest tooth 3 



Posterior width of skull, estimated 78 Width of same tooth at base 1 .5 



Length of orbit 18 Length of postorbital 27 



Width of orbit 12 Width of postorbital 14 



Genus EOSERPETON Moodie, 1909. 



MOODIE, Jour. Geol., xvn, pp. 76-79, fig. 20, 1909. 



MOODIE, Bull. Am. Mus. Nat. Hist., xxvi, p. 355, pi. Ixiii, fig. i, 1909. 



Type: Eoserpeton tenuicorne Cope. 



The genus was proposed for the reception of a single species originally referred 

 by Cope to Ceraterpeton (C. tenuicorne). The species can not be placed in the genus 

 Ceraterpeton on account of the form and structure of the skull, which varies widely 

 from that of the type species, Ceraterpeton galvani Huxley, from the Kilkenny Coal 

 Measures of Ireland. The most important character in which the present species 

 differs from C. galvani is the peculiar form taken by the squamosal and by the posi- 

 tion of the "horn." These characters will be evident on referring to figure 25. No 

 undoubted remains of Ceraterpeton have been found outside the British Isles. Fritsch 

 referred (251) a species, previously described as Scincosaurus crassus, to this genus, 

 but Andrews (8), Jaekel (347) and Woodward (630) all unite in placing the species 

 in the genus where it was formerly described. Jaekel even says that the Scinco- 

 saurus has no horns, so far as he can determine. Cope referred 3 species (123) 

 from the Linton Coal Measures of Ohio to the genus Ceraterpeton, but it has been 

 shown elsewhere (347) that no one of them belongs in the genus, nor in fact do 

 they all belong in one genus. 



Eoserpeton tenuicorne Cope. 



COPE, Geol. Surv. Ohio, n, pt. n, pp. 372-373, pi. xlii, fig. 2, 1875. 

 COPE, Proc. Am. Phil. Soc., xxn, p. 407, 1885. 

 COPE, Proc. Am. Phil. Soc., xxxvi, p. 85, pi. iii, fig. 2, 1897. 

 MOODIE, Proc. U. S. Nat. Mus., vol. 37, p. 23, 1909. 



Type : Specimen in the American Museum of Natural History. There are also 

 specimens Nos. 4472 and 4473 in the U. S. National Museum. 



Locality and horizon: Linton, Ohio, Coal Measures. 



The species was founded on a complete skull preserved on obverse sides of a 

 block of coal. Cope (123, pi. XLII, fig. 2) figured this skull. The figure is poorly 

 executed and does not do justice to the specimen, which is really well preserved. 

 In general the skull is oval, with the orbits located well towards the acuminate 

 snout. The interorbital space is equal to twice the width of the orbit. The pineal 

 foramen lies near the center of the skull. The quadrate angles are drawn out into 

 slender acuminate, longitudinally striate horns, processes from the squamosal. 

 The "horn" arises from an expanded base, which is a portion of the cranial element 

 at the postero-lateral angle of the skull. This character is taken as the distinctive 



