136 NOK'TH AMERICAN FAUNA. [no. 16. 



nists who kindly determined special species or s[)ecial geucra aic ]\Irs. 

 N. L. lirittoii, ^[r. Fredciitk V. Coville, Prof. W. H. Dudley, :\rr. :\I. L. 

 Fernald, Mr. John I>. Leiberg-, Mr. C. L. Pollard, Dr. B. L. Robinson, 

 Dr. J. N. Fvose, Prof. P. A. Rydberg, Mr.- J. K. Small, and Prof. Wil- 

 liam Trelease. In order to properly place the credit for this assistance, 

 the botanist responsible for the identification is in each instance men- 

 tioned. Where no one is named I am personally responsible. 



A few mosses and ferns were found in the tind)erlinc region of 

 Shasta. The mosses, kindly determined by ^Irs. Britton, are liar- 

 pidiion {^. e.rannulatuin Oumb.), Auhtconnrnim niaJroiiiimon Sell., and a 

 species of Fhllonoila. They are conlined rather closely to the borders 

 of the al[)ine streams, where the AiildcoiiDiiion forms coiiijjact mats of 

 a yellowish color. 



The ferns have been determined by 3Ir. William R. Maxon througli 

 the courtesy of Mr. Frederick V. Coville, curator of the National Her- 

 barium. The species which grow sparingly 'n the heather meadows and 

 under the edges of rocks near timberline are : Dvyoptcris ((cidcatu scopu- 

 Ji)i(( (T^aton), Cy.stopferis fragUis (L.) Bernh., ClieihnitJtcs gracillinia 

 D. C. Eaton, ('ri/pto(ir<(mme acrostiehoides R. Br., and PJief/opteris alpvs- 

 iris (Iloppe) Mett. Much lower down, along the boundary between 

 the Canadian and Transition zones, J'tcris (UjuUina lamujinosa (Bory) 

 Hooker, and Asj)1i'niiiin fili.rfo'minH (L.) Bernh. occur. The brake 

 {Pteris) is very abundant on the i)umice sand at Wagon Camp and 

 Sisson and wherever there is suriicient moisture in the soil in spring 

 and early summer. The black-beard lichen {AIertori<( frcmonti) and the 

 handsome yellow tree lichen [Erernia vi(lpiii<() abound in the dark forest 

 of Shasta firs, 



Jn the chapter on 'Life Zones' the more distinctive species have 

 been grouped according to their vertical distribution (see pp. 52-68), but 

 for c()nvenien(;e in finding the notes relating to particular species, 

 they are here arranged in systematic order. In the case of certain 

 plants found by us only on the borderland between adjacent zones, the 

 zone position is in doubt and must be determined by future study. 



The most important kinds of plants from the standpoint of geo- 

 gra])hic distribution are naturally those that remain longest in :i i)ai- 

 ti(nilar spot. Hence, as pointed out by Coville,' trees, shrubs, and 

 perennials are the kinds most useful in determining zone boundaries. 

 For this reason little attention is here given to aunnnls. 



Pinus monticola Douglas. Silver i'ine: Mountiiin White Pine. 



('ointiion in ])l;H'es, chielly in the upper h:ilf of the Canadian zone, 

 bill loc;il and liy no means generally distiibiited. \\liere\cr it occurs 

 it is mi.xed with Shasta iiis, and in i)]aces itieaches ni)high enough to 

 overlap the lower edge of the black alpine hemlocks and white-bark 

 tiinlx'iiine ])ines. (See ]). "S'^.) 



' I'.otMiiy ol' l)(i;itli N alley I'.xihmI i I ion, p).. 17-lS, ISila. 



