warm  an.]  SIXTH    TO    EIGHTH    ANNUAL    REPORTS.  13 
Sixth  Annual  Report  of  the  United  States  Geological  Survey  to 
the  Secretary  of  the  Interior  1884-'85  by  J.  W.  Powell  Director 
[Vignette]     Washington     Government  Printing  Office     1885 
8°.  xxix,  570  pp.,  65  pis.  and  maps.  Bound  in  dark  maroon  cloth  (Survey  edition). 
Out  of  stock.     Separates  of  the  various  papers  were  issued,  in  paper  covers. 
Report  of  the  Director,  pp.  xv-xxix,  pis.  i-iii. 
Administrative  reports  of  chiefs  of  divisions,  pp.  1-101,  pis.  iv-x. 
Mount  Taylor  and  the  Zuni  Plateau,  by  Capt.  Clarence  E.  Dutton,  pp.  105-198, 
pis.  xi-xxii. 
Preliminary  paper  on  the  driftless  area  of  the  upper  Mississippi  Valley,  by  T.  C. 
Chamberlin  and  R.  D.  Salisbury,  pp.  199-322,  pis.  xxiii-xxix. 
The  quantitative  determination  of  silver  by  means  of  the  microscope,  by  Joseph 
Story  Curtis,  pp.  323-352,  pi.  xxx. 
Preliminary  report  on  seacoast  swamps  of  the  eastern  United  States,  by  Nathan- 
iel Southgate  Shaler,  pp.  353-398. 
Synopsis  of  the  flora  of  the  Laramie  group,  by  Lester  F.  Ward,  pp.  399-557,  pis. 
xxxi-lxv. 
Index,  pp.  559-570. 
Seventh  Annual  Report  of  the  United  States  Geological  Survey  to 
the  Secretary  of  the  Interior  1885-86  by  J.  W.  Powell  Director 
[Vignette]     Washington     Government  Printing  Office     1888 
8°.     xx,  656  pp.,  71  pis.  and  maps.     Bound  in  dark  maroon  cloth  (Survey  edition) . 
Out  of  stock.     Separates  of  the  various  papers  were  issued,  in  paper  covers. 
Report  of  the  Director,  pp.  3-42. 
Administrative  reports  of  chiefs  of  divisions,  pp.  43-143,  pis.  i-vii. 
The  rock  scorings  of  the  great  ice  invasions,  by  T.  C.  Chamberlin,  pp.  147-248, 
pi.  viii. 
Obsidian  Cliff,  Yellowstone  National   Park,  by  Joseph  P.  Iddings,  pp.  249-295, 
pis.  ix-xviii. 
Report  on  the  geology  of  Marthas  Vineyard,  by  Nathaniel  S.  Shaler,  pp.  297-363, 
pis.  xix-xxix. 
On  the  classification  of   the  early  Cambrian  and   pre-Cambrian  formations,  a 
brief  discussion  of  principles,  illustrated  by  examples  drawn  mainly  from  the 
Lake  Superior  region,  by  R.  D.  Irving,  pp.  365-454,  pis.  xxx-li. 
The  structure  of  the  Triassic  formation  of  the  Connecticut  Valley,  by  William 
Morris  Davis,  pp.  455-490,  pi.  lii. 
Salt-making  processes  in  the  United  States,  by  Thomas  M.  Chatard,  pp.  491-535, 
pis.  liii-lv. 
The  geology  of  the  head  of  Chesapeake  Bay,  by  W  J  McGee,  pp.  537-646,  pis. 
lvi-lxxi. 
Index,  pp.  647-656. 
Eighth  Annual  Report  of  the  United  States  Geological  Survey  to 
the  Secretary  of  the  Interior  1886-'87  by  J.  W.  Powell  Director 
[In  two  parts]  Part  I  [-II]  [Vignette]  Washington  Government 
Printing  Office     1889 
8°.     2  pts.     xix,  474,  xii  pp.,  53  pis.  and  maps;  1  prel.  1.  (title),  475-1063  pp.,  54-76 
pis.  and  maps.     Bound  in  dark   maroon  cloth    (Survey  edition).     Out  of  stock. 
Separates  of  the  various  papers  were  issued,  in  paper  covers. 
Pt.    I.  Report  of  the  Director,  pp.  3-93,  pi.  i. 
Administrative  reports  of  chiefs  of  divisions,  pp.  95-257,  pis.  ii-xv. 
Quaternary  history  of  Mono  Valley,  California,  by  Israel  C.  Russell,  pp. 
261-394,  pis.  xvi-xliv. 
