THE MICROSAURIAN FAMILY NYRANIID/E. 137 



Micrerpeton caudatum Moodie (462, 478) from the Mazon Creek, Illinois, beds, and 

 Sir William Dawson (208) described scales accompanying several forms from the 

 Joggins deposits of western Nova Scotia. 



MEASUREMENTS OF THE TYPES OF ICHTHYERPETON SQUAMOSUM MOODIE. 



Length of animal as estimated from two impressions 3 ft. 



Length of longest impression 21 in. 



Length of specimen containing tail impression 9 in. 



Width of tail impression: Maximum 50 mm. 



Minimum 6 mm. 



Width of a single scale I mm. 



Distance from base of tail to tip 125 mm. 



Length of specimen as preserved 225 mm. 



Width of chevron rod space 30 mm. 



Length of rib 25 m m . 



8 chevrons in a distance of 3 mm. 



Genus CERCARIOMORPHUS Cope. 



COPE, Proc. Amer. Phil. Soc., 1885, p. 405. 



Type: Cercariomorphus parvisquamis Cope. 



The type specimen of this genus is supplemented by a portion of the body of 

 another specimen which adds a little to our knowledge of the animal's form, but 

 nothing as to structure. Cope's original description is as follows: 



"Represented by a fusiform body which terminates in a long, slender, cylindrical tail, 

 and which is covered with small subquadrate scales quincuncially arranged. No fins or 

 limbs are preserved, and the form of the head can not be made out. Probably a portion 

 of the skull is preserved. There are some scattered bodies in the body portion, which 

 look like deeply concave vertebrae with the zygapophyses of batrachians. There are some 

 linear impressions at one point, which resemble the bristle-like rods on many Stegocephali. 

 They are so few as to be of little importance. The scales are like those of fishes. There 

 are traces of segmentation in the axis of the long tail. 



"The position of this curious form is quite uncertain. It is quite different from any- 

 thing observed hitherto in the American Coal Measures." 



Cercariomorphus parvisquamis Cope. 



COPE, Proc. Amer. Phil. Soc., 1885, p. 405. 

 MOODIE, Science, n.s., XLI, No. 1056, p. 463, 1915. 



Type : Specimen No. 2560, Newberry Collection, American Museum of Natural 

 History. 



Horizon and locality: Discovered by Samuel Huston at the Linton, Ohio, Coal 

 Mines. (Plate 21, figs. 3, 4; 24, figs. 2, 3.) 



The scales (plate 24, fig. 2) in their present condition are entirely smooth. At a 

 distance of 20 mm. from the base of the tail they are in 20 longitudinal series. At 

 that point the transverse diameter of the body is 140 mm. The outline contracts 

 rather abruptly to the tail, of which 66 mm. are preserved. The surface of the tail is 

 obscured by a thin layer of carbonaceous matter not sufficiently thick to obscure 

 scales, which are evident at distances of 16 mm., 43 mm., and 52 mm. from the tip. 

 The scales on the tail are smaller than those on the body and are without markings 

 of any kind. The anterior half of the body is depressed and distorted, but the 

 remainder is well preserved and shows a fairly good outline of an apparently 

 limbless body. 



