THALESTEIS. 135 



of the foregoing; penultimate joint much smaller. 

 Anterior antennae of the male shorter and swollen, 

 third joint very short and constructed, fourth much 

 the longest and as wide as the two basal joints, armed 

 with a long falciform appendage, fifth and sixth joints 

 about half the length and breadth of the fourth, 

 seventh and eighth very small, last joint as long as the 

 fifth, but very narrow ; a few crowded setae on the 

 margin of the second joint, and three small ones at 

 the apex of the last joint : inner branch of posterior 

 antennae 2'jointed. Mouth-organs as usual in the 

 genus. Lower foot-jaw (PI. LXIII, fig. 15) terminat- 

 ing in a slender clawed hand, in shape approaching that 

 of T. longimana, the hand being irregularly angular 

 and subcrescentic, with the internal angle slightly 

 setose ; the claw strong and well curved. First pair 

 of swimming-feet (PI. LXII, fig. 14) almost as in T. 

 longimana, except that the terminal claws and setae 

 are longer and more slender, the two branches being 

 nearly equal, and the long claw equal in length to the 

 branch itself. The inner branch of the second pair of 

 feet in the male is, as usual, 2-jointed (PI. LXII, fig. 15), 

 the three terminal spines being uncommonly small 

 and slender (a). Fifth pair of feet in the female 

 (fig. 16) having both branches of nearly equal length, 

 the inner branch broad, sub-quadrate, and bearing five 

 setae on the distal extremity, the margins between the 

 setae ciliated; outer joint smaller, ovate, with six 

 terminal setae, four of which are small and slender, 

 the apical two being larger. The fifth foot in the male 

 (fig. 17) is smaller; inner segment short and broad, 



