SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 103, NUMBER 9 



MYSTACOCARIDA, A NEW ORDER OF 



CRUSTACEA FROM INTERTIDAL 



BEACHES IN MASSACHUSETTS 



AND CONNECTICUT 



(With Two Plates) 



BY 



ROBERT W. PENNAK 



Biology Department, University 



of Colorado 



AND 



DONALD J. ZINN 



Osborn Zoological Laboratory, 



Yale University 



(Publication 3704) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



FEBRUARY 23, 1943 



