Contents

07 April 1972
Vol 176, Issue 4030

About The Cover

``Pure tone'' bat (Chilonycteris parnellii) emitting orientation cries. The meagphone-shaped mouth aids in the forward beaming of echolocation pulses while the funnel-shaped ears are advantageous for the reception of echoes. See page 66. [William Sacco, Biology Dept., Yale University]