498 GEOFFREY SMITH. . 
lives among weeds in the littoral region of the lake, rather 
after the manner of a prawn, and pursues more of aswimming 
habit than the rest of the order to which it belongs. This 
habit and the characters correlated with it are therefore 
most probably a fairly recent acquisition. 
The other living representative, Koonunga cursor, is a 
little marbled-grey animal which differs from Anaspides in 
several important characters, such as the possession of sessile 
in place of stalked eyes, the entire absence of a scale on the 
second antennee, and the presence of only seven free thoracic 
segments, but it closely resembles Anaspides in general 
appearance, especially in its habit of running with the body 
held straight and unflexed. 
Of the fossil forms we can say for certain that they 
followed a similar mode of life to Anaspides and 
Koonunga. There is no trace in any of them of a true 
dorsal flexure, the fossils being in many cases preserved with 
the body quite straight as in the normal walking position of 
Anaspides. ‘The tail-fan is small, the external scales not 
enlarged, and the eyes either shortly pedunculated or possibly 
in some cases absent. 
The most perfect resemblance to Anaspides is afforded 
by the English carboniferous fossil Preeanas pides, described 
by Woodward. The segmentation and posture of the body, 
the detailed jointing of the limbs and antenne in this fossil 
so exactly reproduce the corresponding features of the living 
Anaspides, that so far from there being any doubt as to 
the two forms being referable to the same order, it is 
justifiable to include them in the same family. The entire 
absence of the characteristic leaf-like gills in this and all the 
other fossil Syncarida is unfortunate, but we could hardly 
hope that these extremely delicate and perishable structures 
should be preserved for us in a fossil state. 
With regard to the other fossils, although there can. be 
small doubt that we are dealing with allied forms, it is difficult 
to be certain about details). Gampsonyx (text-fig. 53) has 
a very similar body form and segmentation to Anaspides, 
