GEOLOGIC FORMATIONS 739 



localities (Qlv) contains a fauna comparable to the fauna of the Stephen 

 formation in the Canadian Pacific Eailway section, and is represented in 

 our collections from the mountain (Titkana) itself by a locality 600 feet 

 above the base of the formation. The second of the two localities {611 

 and 617??,) is represented in our collections from both Titkana Peak and 

 "Mount Hitka" by a locality at the base of the formation 600 feet below 

 the horizon of the Stephen fauna. 



(§25&.) As has been described under the "Hitka" (§§ 12 and 27h), 

 there appears to be duplication involving that formation and the Titkana. 

 Our reason for choosing the term Titkana and abandoning the Hitka is 

 that while the former is stated to be unfossiliferous, Walcott found two 

 fossil horizons in the Titkana, and the latter formation is much better 

 exposed in the peak of the same name than is the Hitka in Mount Hitka. 

 A comparison of the abundant fossils found in many horizons of the 

 "Hitka" and the Titkana confirms their identity. 



''MUMM LI3IESTONE8'' (§ 26) 



(§ 26a.) According to Walcott, the "Mumm limestones" are Middle 

 Cambrian, massive-bedded, gray, arenaceous limestones w^eathering to 

 gray and buff tints, with an estimated thickness of 600 feet, and occur 

 (1) in the northwest base of Titkana Peak (= Tatei limestones), (2) 

 on the westward slope of the ridge east-northeast of the lower end of 

 Lake Adolphus (= Tatei limestones), and (3) in the upper part of 

 Mumm Peak (= Hota limestone). No fossils were found. 



(§266.) As has been stated already (§16), inspection of the rocks 

 forming the top of the mountain proved them to belong to the Chetang, 

 a formation which is described by Walcott as lying 2,500 feet below the 

 "Mumm," and is, according to his section, separated from that forma- 

 tion by two other formations. The Mumm limestones are, therefore, 

 non-existent, so far as Mumm Peak is concerned — in fact, the limestone 

 to which the name was there applied is the "Hota" (§§ 306, 30^, and 

 32c). We have shown (§§ 28 and 276) that the limestones in localities 

 1 and 2 above are to be referred to the Tatei, and that there is a duplica- 

 tion in Walcott's section which involved the confusion of the Mumm with 

 the Tatei and the Hitka with the Titkana. The absence of any fossils 

 in Walcott's collections from the Mumm, Hitka, and Tatay formations, 

 3,100 feet, made the identification of his section in the field a slow 

 process, the problem being further complicated by the facts (a) that 

 neither the Mumm limestone nor an}^ limestone of the age assigned to 

 the Mumm occurs in the mountain in which it is stated to be typically 

 developed (§ 32c), and (6) that the "Hitka," in the mountain of that 



