BY U. II. SCOTT AND CLIVJE E. LORD. 93 



We do not imagine for one moment that we have 

 cleared up all the mysteries that surround the. Nototheria, 

 but we hope we have so recapitulated the facts that the 

 discoveries of the future may work more or less smoothly 

 into line, and perfect our knowledge of the wonderful 

 giants of pleistocene, days. 



When variations of the mandibalar symphyses, 

 bounding lines of horizontal rami — namely, contour lines, 

 angles of coronoid processes, positions of dental foramina, 

 etc., have all d bo the s< cti< n ln-aded — 



"Characters displayed during growth from immaturity to 

 "maturity" — there still remains the mati rial used by us 

 for outlining our two groups of Megacerathint and 

 Leptocerathine animals, and so for the present, we 

 tho subject with that taxonomic settii 



THE HORN IN THE LEPTOCERATHINE GROUP. 



Professor W lie lighting bosses in Noto- 



therium ta > was that of bony emin< nces a 



with skin. Ii' we take an analogy from the Ungulai 

 get— 



1. Rudimentary, skin covered bosses in Horses, as an 



abnormal condition. 



2. Skin and hair covered bosses in Giraffes. 



tnong the gigantic un of the A ter- 



tiary s of bony bosses obtain. 



THE EVOLUTIONARY TREND. 



To appreci the little we know of the evolu- 



tionary trend among the marsupials that culminal d in 

 the Nototherian stirp, ii will 1 ry to tabula: 



variou therein, with special reference 



to a geological succession. 



PRE-EOCENE. 



From Pre-Eoccne times, tho Nototheria retain — 



A. Marsupial anatomy generally. 



B. Well developed clavicles, relating to pouch 



manipulation by the hand and forearm. 



C. Five fingers and fi\ 



ricondyloid foramen to the humerus. 



