14 MR. 0. A. SAYCE ON A REMARKABLE 



From these two groups the following fundamental external differences occur : — Absence 

 of a carapace, presence of a double series of leaf-like epipodial branchiae on the thoracic 

 limbs, which are seven-jointed and well adapted for walking, also the presence of an 

 auditory organ in the base of the upper antenna?. In all of these Anaspides also agrees. 



It must be acknowledged that until more is known of the internal anatomy and 

 embryology of the Anaspidacea the systematic position is rather uncertain. I understand 

 from Mr. Geoffrey Smith that he will shortly rnake a further contribution to our 

 knowledge of the anatomy of Anaspides, and, if opportunity permits, I hope to do some- 

 thing for Koonunga during this year. I am alive to the importance of a knowledge of 

 its embryology, and will do my best to procure material for this also. 



In respect to other forms that bear a rather close resemblance in some important 

 characters to the present species, I may refer the reader to Dr. Caiman's paper in the 

 Journal Linn. Soc, Zoology, xxvii. (1899) pp. 338-344, on Bathynella wataras, Vejdovsky, 

 a minute crustacean taken from a well in the city of Prague, and also to his remarks 

 concerning some forms from the Palaeozoic Coal-Measures (Trans. Roy. Soc. Edinburgh, 

 xxxviii. (1897) pp. 796-S01). Restored drawings are there given, with valuable remarks 

 on the comparison with Anaspides. 



EXPLANATION OP THE PLATES. 



Plate 1. 



Koonunga cursor. 



Fig. 1. Side view of whole animal, a male, x 16. 



2. Outline of a female, dorsal view, x 13. 



3. Side view of cephalon and first segment of person, x 37. 



4. Ventral view of appendages of cephalon and of first segment of perseon in situ, X 37. 



5. Part of antennule of a female, from above, x 37. 



6. Part of antenna, x 37. 



7. Part of antennule of a male from underneath, showing sexual modifications, x 200. 7 a. Part 



of the surface-armature of male organ in side view. 



8. Anterior lip, X 45. 



9. Posterior lip, x 37. 



10. Mandible of right side, x 75. 



11. Mandible of left side, x 75. 11 a. Showing continuity of cutting-plate and molar expansion, 



increased magnification. 



12. First maxilla, x 127. 



Plate 2. 



Fig. 13. Second maxilla, x 127. 13 a. Palp, x 195. 

 14. Maxilliped, side view, x 45. 

 ].". First appendage of the perseon, X 45. 



16. Part of the fifth appendage of the person of a female, showing the inner coxal lobes of each 

 side in normal position, x 45. 



