242 Kansas Academy of Science. 



while others exhibit highly developed endochondrium, and this oc- 

 curs in forms which we place in the same genus — for instance 

 Tuditanus punctalatxis Cope and Taditanus minimus Moodie. 

 Just what this may mean remains to be determined. It is possible 

 that it is due to the mode of preservation. 



Another form of the greatest interest is the one recently de- 

 scribed by the writer from the Mazon Creek beds of Illinois a& 

 Micrerpeton caudatum. This interesting little fossil is less than 

 two inches in length, but there are preserved in its matrix more 

 characters than we would expect in many specimens of fossil 

 amphibians. The form represents the only species of Branchio- 

 sauria so far discovered in North America. On the small nodule 

 in which Micrerpeton is embedded there are found a nearly com- 

 plete outline of the body, a nearly complete skeleton; the black 

 pigment of the eyes; the, pigment of skin and the pattern it as- 

 sumed; minute scales which covered the body; the lateral line 

 canals of the tail, and the ventral scutes — enough, in fact, to war- 

 rant a restoration of the animal, and this has been given. (Plate 



II, fig. 1.) 



Another form which will interest us here is the one described in 

 1865 by Cope under the name of Amphihamus grandiceps. Thia 

 form is known from nearly complete remains which have been de- 

 scribed by Dr. (). P. Hay, and again described by the writer with 

 a restoration. The form is interesting as being a typical member 

 of the Microsauria. (Plate III.) It had a short, stumpy tail, a 

 short body, and a short, broad head It had four toes on the. hand 

 and five on the foot, with the phalangeal formula of 2, 2, 3, 2 for 

 the hand and of 2, 2, 3, 4, 3 for the foot. The skeleton of the ani- 

 mal has been restored, with an outline of the body. 



Still another form is the one described by Cope as Molgophis 

 niacrurtis, which had neither limbs, ribs nor ventral armature, but 

 consisted merely of a very elongate vertebral column consisting of 

 nearly 100 minute vertebrae and a sharp-pointed skull. This form 

 resembles in great degree the modern whipsnake of Kansas in form 

 and proportions, though it was scarcely ten inches in length. 



I have described for you now five forms, which we will try to 

 discuss in the light of our present knowledge in regard to their 

 classification. The first form, Pelion lyelli Wyman, is an aberrant 

 form and may be related to the irogs. It has been placed in the 

 Branchiosauria and in the Microsauria. It belongs in neither, but 

 may be placed provisionally in the latter group. The form Isodec- 

 tes copei Williston has been shown to be a true reptile, and we 



