506 BULLETIN 54, UNITED STATED NATIONAL MUSEUM. 



The ventral surface of the last segments of the thorax and the first 

 vsegments of the abdomen has longitudinal keels as is usual. 



The abdomen is also very characteristic; the prolongations of the 



b c 



FIG. 553. lONE BREVICAUDA (AFTER BONNIER). a, DORSAL VIEW OF ADULT FEMALE. 6, DORSAL 

 VIEW OF MALE. C, VENTRAL VIEW OF FEMALE, d, FIRST INCUBATORY LAMELLA. , VENTRAL 

 VIEW OF HEAD OF FEMALE (RIGHT MAXILLIPED REMOVED). /, BUCCAL ROSTRUM AND ANTENNA OF 



FEMALE, g, ABDOMEN OF FEMALE (DORSAL VIEW), h, EXTREMITY OF MAXILLIPED. i, LEG OF 

 FEMALE, j, LONGITUDINAL SECTION OF VENTRAL PORTION OF FIRST INCUBATORY LAMELLA. 

 k, HEAD OF MALE (VENTRAL SIDE). 



pleural lamellae are here very much more developed than in the Euro- 

 pean species and they increase in length from the first to the sixth, 



