THALESTRIS. ioe 
7. THALESTRIS SERRULATA, nov. sp. Pl. LIX, figs. 2—11. 
Male.—Body elongated, of nearly equal thickness 
throughout, first segment unusually small. Anterior 
antenna short and robust. Inner branch of posterior 
antenna 2-jointed. Posterior foot-jaw (fig. 7) very 
strong, hand broad, sub-quadrate, outer margin 
strongly arched, inner sinuous and fringed with two 
separate rows of spine-like cilia, the distal row sub- 
erescentic and tending inwards towards the middle 
of the hand; terminal claw stout, falciform, about 
half the length of the hand; first joint bearing a 
spine and three or four setz at the extremity of its 
inner margin. Outer branch of the first foot much 
more slender than the inner (fig. 8), terminating in 
two long, slender spines, and a short seta; outer 
margin closely ciliated, having a short seta below the 
middle and one at the apex of the first joint; pedun- 
cle armed at the outer angle with a broad plumose 
seta, and at the inner with a stout curved spine; inner 
branch very broad, and bearing a seta near the middle 
of its inner margin, outer margin ciliated, terminal 
claws twe, one long and one short; these, as well as 
the claws of the outer branch, are closely and finely 
pectinated on the concave margins ; outer margins of 
all the swimming-feet friged with spines. Inner branch 
of the fifth foot (fig. 9) short, broadly triangular, 3- 
setose; outer branch elongate sub-ovate, inner margin 
ciliated, outer with three or four short and one long 
