LICHENS 
T 43 
212. Cetraria islandica delisei (Bory.) Schaer. 
Cetraria delisei Bory in Schaerer, Enum. 16. 1850. 
Cetraria islandica delisei Schaerer, Enum. 16. 1850.— Westr. Faergh. /. 
16 c. 
Hall Island (Trelease, 1197); St. Matthew Island (Trelease, 1195, 
1205); St. Lawrence Island (Trelease, 1196); Plover Bay, Siberia 
(Trelease, 1199); Cape Nome (Setchell). Recorded by Farlow as 
having been collected on the expedition to Point Barrow; J. M. Ma- 
coun collected it on St. Paul Island; Nylander credits it to St. 
Lawrence Island. 
It is noticeable that the development of the marginal fibrils is very- 
slight in the variety delisei. No. 1205 from St. Matthew Island 
shows a few fibrils on the finer branches, near the apex of the fronds. 
All these forms are somewhat coarser than those of the variety de¬ 
lisei in the Tuckerman Herbarium, and all are sterile. With the 
specimen from Flail Island is a species of Dicranum. 
213. Cetraria islandica platyna (Ach.) Th. Fr. 
Cetraria platyna Acharius, Syn. 229. 1814. 
Cetraria islandica platyna Th. Fries, Lich. Arct. 35. i860. 
Hall Island (Trelease, 1201, 1202); St. Lawrence Island (Tre¬ 
lease, 1200) ; Plover Bay, Siberia (Trelease, 1203). New to the 
Alaska region. 
The specimens of this variety have a much richer chestnut color 
than the type, while the surface of the thallus is very highly polished 
and the marginal fibrils are very slightly developed. Not mentioned 
in Tuckerman’s Synopsis of N. A. Lichens, but given by Fries as 
occurring in Greenland. 
214. Cetraria arctica (Hook.) Tuck. 
Dnfourca arctica Hooker in Richards., Frank!. Narr. 762, append. 47. t. ji. 
1823. 
Cetraria arctica Tuckerman, Syn. N. A. L. 1: 30. 1882. 
Locality lost (Trelease, 1236) ; St. Matthew Island (Coville and 
Kearney, 2117a); Plover Bay, Siberia (Trelease, 1237; Coville and 
Kearney, 1S50). Sterile. Reported by Farlow as occurring at Point 
Barrow; collected by Macoun on St. Paul Island, and by Dr. Hayes at 
Taku. Hooker and Arnott report it from Kotzebue Sound under the 
synonym Dt<fourea arctica Br., and Nylander records its occurrence 
at Port Clarence and on St. Lawrence Island under the synonym Dac- 
tylina arctica (Hook.). 
Mixed with it are Cetraria islandica and various mosses. 
