ILYOPSYLLUS. 143 
Genus 27. Inyvorsytuus, Brady and Robertson (1873). 
Body tumid and gibbous. Anterior .antenne 
very short, 5-jointed, basal joint greatly dilated ; 
posterior stout, destitute of a secondary branch. 
Mandibles small, and bearing a simple bisetose palp. 
First pair of feet stout, and strongly spined, internal 
branch composed of one, external of three joints, 
second, third, and fourth pairs having both branches 
tri-articulate. Abdomen short and tapering towards 
the extremity ; caudal sete spathulate. 
1. Ityorsyiius coriaceus, B. and &. Pl. LXXXIT, 
figs. 1—10. 
Ilyopsyllus coriaceus, B. and R. Ann. and Mag. Nat. Hist., 
ser. 4, vol. xii, p. 132, pl. ix, figs, 1—5 
(1873): 
Body very tumid; seen laterally (fig. 2) the ventral 
line is almost straight, the dorsal excessively arched, 
so that the cephalothorax forms almost a semicircle ; 
seen from below (fig. 1), the outline is like that of a 
spear-head rounded off in front; greatest width situate | 
in the middle, and equal to half the entire length of 
the body; posterior half abruptly tapered. First 
cephalothoracic segment very large, forming half the 
length of the animal. Anterior antennz (fig. 3) 5- 
jointed, sparingly setose, very minute, the basal joint 
