IDYA. 171 
Genus 32. Ipya, Philippi (1848). 
(Tisbe, Lilljjeborg, Claus.) 
Cephalothorax broad and somewhat depressed ; 
abdomen narrow, 5-jointed. Head coalescent with 
the first thoracic segment. Anterior antenna 7- or 
8-jointed, elongated; inferior 3-jointed, with a large 
4-jointed secondary branch. Mandible long and 
strongly toothed; palp 2-branched, basal joint short, 
branches 1-jointed, long and slender, setiferous at the 
apices. Maxilla armed with several slender terminal 
teeth; palp well developed. First and second foot- 
jaws nearly alike, uncinate; first pair 2-, second 3- 
jointed. Inner branch of the first pair of feet 2- 
jointed, clawed; outer branch short, 8-jointed; the 
three following pairs having both branches 3-jointed. 
Fifth pair elongated, 2-jointed. 
In the tendency to flattening and lateral expansion 
of the cephalothorax, and the uncinate form of the first 
foot-jaws, as well as in the dilatation and peculiar 
armature of the first pair of feet and the elongated 
fifth foot, this genus exhibits a distinct departure 
from most of the Harpacticide which have been 
described in the foregoing pages. These characters 
are even more marked in the next succeeding genus, 
Scutelidium. The genus Harpacticus, in the struc- 
ture of the first pair of feet, and Zaus, both in that 
character and in the lateral expansion of the body, 
