ON THE ANASPIDACEA, LIVING AND FOSSIL. 563 
the separate segment bearing the exopodite having probably 
fused with the third segment, as in Koonunga and the 
posterior limbsof Anaspides. All the thoracic limbs except 
the last were apparently furnished with exopodites. 
The abdominal appendages were probably very much as in 
Anaspides, the exopodites being furnished with long, slender 
hairs. 
For the determination of specific characters probably the 
hind segments, telson and uropods are most important. 
The dorsal posterior borders of the third, fourth, fifth and 
sixth abdominal segments have a moniliform ornamentation 
showing where a row of spines was situated. The telson is 
elongated and bluntly rounded at the end. Its lateral 
borders are setose almost to the base, and at the posterior 
lateral angles a few longer sete were present. 
The uropods do not project further than the end of the 
telson. The outer ramus has a row of about seven short 
sete on its outer border and two elongated spines at the line 
of segmentation near the tips of this ramus. 
Length.—Largest specimen 57 mm. in length. 
Occurrence.—In clay-ironstone nodules of the Coal- 
measures near Ilkeston, Derbyshire. 
Family Il. Koonungide (Sayce 10 and 11). 
The thorax is composed of seven distinct somites, the 
anterior one being fused with the head. The eyes are sessile. 
First antenne of male with sensory modification. There is 
no antennal scale. The mandible has a cutting blade and a 
setose lobe, but no molar expansion. The palp of the first 
maxilla is reduced, but distinct, and carries sete. ‘The first 
thoracic limb has a slender exopodite, but is without gnatho- 
basic lobes. The thoracic limbs are composed of only seven 
segments. The last two thoracic limbs are uniramous. The 
pleopods are all uniramous, except the first two pairs in the 
male, which are modified as copulatory organs and retain their 
endopodites. 
