12 



MK. 0. A. SATCE ON A EEM ARK ABLE 



Dr. Caiman (Ann. & Mag. Nat. Hist. (7) xiii. p. 152), and I emphasise the facts for 

 others to accept for what they are worth. 



The fifth, sixth and seventh appendages of the perseon are in close agreement 

 with the fourth. The appendages of the pleon (fig. 23) are, with the exception of the 

 terminal ones (uropoda), quite inconspicuous and functionless, appearing only as 

 minute one-jointed papilla? on each somite. The uropoda and telson are, however, 

 quite similar to those of the adult form. 



Habitat. The only locality where Koonunga so far has been found is a small extent 



of shallow marshy country through which a tiny rivulet flows, at Ringwood, near 

 Melbourne. The water is almost entirely dried up for a few months each summer, 

 and indeed is entirely so during some years of less rainfall. The elevation is but 

 slightly above sea-level. 



The little crustaceans inhabit the small weedy pools and they are remarkably 

 active ; their usual form of locomotion is running, but they can swim rapidly. On 

 one occasion I saw one swimming on its back, just as some Phyllopoda do, but this 

 is quite exceptional. On most of those examined there were a number of sedentary 

 Eotifera of the genus Floscidaria, and these were lodged principally on the branchiae. 



Systematic Position of Koonunga. 



The foregoing description will have amply demonstrated the relationship of the 

 sessile-eyed Koonunga to the stalk-eyed Anaspides, and warrants my placing them 

 together in the same order ; and also, I think, proves my previous statement to be 

 justified, that it is the most primitive Edriophthalmatan so far known. 



The following synopsis of characters of these two forms may help to focus the mind 

 upon their features of agreement and disagreement : — 



Koonunga. 



In close agreement, except that the 

 anterior thoracic segment is 

 coalesced with the head. 



Sessile. 



Similar. 



Similar, but no scale. 

 Similar, but no spine-row. 



Two lobes, no exopodite ; palp more 



definite. 

 Similar. 



