CONTENTS. 
PAGE. 
Weewe OO CONTENTS. - oe iiss dae es Hee oe ek AG RR Oe lil 
ae OP COTO oe ee Ce 4a cw rede we een eas Vv 
List or MemsBers. Revised to December 31, 1909...... vi 
1. PATRONS. 
2. Honorary MEMBERS. 
3. ACTIVE MEMBERS. 
WAGE OY TIISPORY i562 es ce cial ne bias eee XVili 
Recorp. January 1, 1908, to December 31, 1909...... Xxil 
Papers PUBLISHED. January 1, 1908, to December 31, 
1909: 
1. Carvin M. Woopwarp.—Air-Ship Propeller Prob- 
lems.—Issued March 14, 1908............... 1 
2. Jutius Hurrer and Jonn K. StTREcKER, JR.— 
The Amphibians and Reptiles of Arkansas.— 
tee, GY 14) 1000 i ete va Cee wh Vac 11 
3. WiLL1AM TRELEASE.—The Mexican Agaves known 
as Zapupe.—Plates I-VI.—Issued May 18,1909. 29 
4. EK. B. Branson.—The Fauna of the Residuary 
Auburn Chert of Lincoln County, Missouri.— 
Plate VII.—Issued May 31, 1909............ 39 
5. H. E. Ewrne.—New North American Acarina.— 
Plates VITI-XI.—Issued August 16, 1909...... 53 
6. Titte Pace. Prefatory Matter and Index of Vol. 
XVIII. Record January 1, 1908, to Decem- 
ber 31, 1909.—Issued July 5, 1910. 
Sey OF AUTHORRS oo i6 cS Ue een eee ea 79 
RUMEMAT, INUME CS Cee ca i cick we ecw abet ames 80 
meee TO CIMNURA es ro ica ve eh emu ncen 82 
