250 University of Calif ornia PubUoations in Zoology V^^oh. 21 



(1897, pp. 695-720). Winge advocated the use of numerals to desig- 

 nate the various molar crown divisions. For the follov^ing translation 

 of Winge 's views the w^riter is indebted to Dr. A. Boving, of the 

 Bureau of Entomology, U. S. Department of Agriculture. 



The three primitive cusps, Avhich are innermost on the teetli of the lower jaw, 

 and outermost on the teeth of the upper jaw, are designated as 1, 2, and 3 ; the 

 cusp marked 2 is the oldest, corresponding to the single cusp of the incisors and 

 canines and to the middle cusp on the two anterior molars. The two more recently 

 added cusps, the outermost on the teeth of the loAver jaw, the innermost on the 

 teeth of the upper jaw, are designated as 4 and 5. The original single heel of 

 the teeth in the upper jaw is designated as 6, the more recently added enlarge- 

 ment of the heel is designated as 7 (Winge, loc. cit., p. 67). 



On the two following pages Winge {loc. cit., pp. 68-69) gives a 

 further explanation of his views on this subject : 



Synopsis of the changes of anterior molars in some mammalsi. 



The three original cusps, innermost in the lower jaw, outermost in the upper 

 jaw, are designated as 1,2, 3 ; the two more recently added cusps, outermost in 

 the lower jaw, innermost in the upper jaw, are designated as 4~^""5; the lieel 

 on the teeth of the upper jaw is designated as 6 whenevei- it is single; as 6 7 

 whenever it is doubled by the addition of a new cusp ; as 6 + 7 when the tAvo are 

 fused or when one of them has disappeared. 



In his "Mammals of Denmark,'' Winge apparently does not 

 adhere to some of his early views. In this work (1908, p. 77), cusps 

 4 and 5 are shovna as being outermost in the teeth of both upper and 

 lower jaws of Microtns arvalis, and according to these figures his 

 numbers for the cusps would have the following equivalents : In the 

 upper molars, 4 and 5 are the paracone and metacone, respectively, 

 and 6 and 7 the protocone and hypocone. In the first lower molar, 

 2 and 3 are equivalent to the metaconid and entoconid, and 4 and 5 

 are equivalent to the protoconid and hypoconid. Winge considered 

 that his cusp "6" was a later addition and that his cusps "1, 2, and 

 3" (=parastyle, mesostyle, and metastyle, according to Barrett- 

 Hamilton, 1914, pi. 28) were the oldest. Barrett-Hamilton {loc. cit.) 

 makes the statement that cusp " 2 " is present in some of the American 

 Cricetinae, while in all the Microtinae this cusp is fused with "4" 

 (= paracone), and thus has completely disappeared. He held, fur- 

 thermore, that the lower molar series was the inverted image of the 

 upper. The considerations which were advanced by Fleischmann 

 (1891, p. 891) and Mahn (1890, p. 652) to show that the anterior 

 end of the lower molars is homologous with the posterior end of the 

 upper ones and vice versa, have been refuted by Scott (1893, pp. 



