294 THE VOYAGE OF H.M.S. CHALLENGER. 



Fig. 14. Somewhat older stage than fig. 3, seen from the same side of the test, measur- 

 ing 8 mm. 



15. Still older stage, measuring 9 mm. First appearance of the genital plates. 



16. Somewhat more advanced than fig. 15, measuring 11 mm. 



17. Older than fig. 16, measuring 12 mm. 



18. Older than fig. 17, measuring 15 mm. 



1 9. Female (abactinal side) with deeply-sunken, broad petaloid ambulacra, and two 

 genital pores ; natural size. 



20. Female with narrower, deeply-sunken petaloid ambulacra, and three genital 

 pores ; natural size. 



Figs. 19 and 20 are not fully grown. 



21. Abactinal system of large male ; magnified. 



22. Abactinal system of large female ; magnified. 

 The largest specimen measuring 50 mm. in longitudinal diameter. 



PLATE XXI. 



Breynia australasice, Gray (figs. 1, 2), p. 177. 



Fig. 1. Seen from the actinal side ; natural size. 



„ 2. Seen from the abactinal side ; natural size. 



Palceotwpus loveni, A. Ag. (figs. 3-16), p. 158. 



„ 3. Enlarged view of denuded specimen, seen from the abactinal side (f). 



„ 4. Same, seen from the actinal side. 



„ 5. Same, seen in profile. 



,, 6. Same, seen facing the anterior extremity. 



,, 7. Same, seen facing the anal system. 



,, 8. Enlarged view of anal system and of subanal fasciole. 



„ 8 a. Plates of actinostome. 



„ 9. Profile view of Palwotropus loveni; natural size, with its spines. 



,, 10. Same, seen from the actinal side. 



,, 11. Same, seen from the abactinal side. 



,, 12. Abactinal system, seen from the interior of the test. 



,, 13. Abactinal system, denuded. 



,, 14. Actinostome, seen from the interior of the test. 



,, 15. Denuded actinostome. 



,, 16. Enlarged view of primary and secondary tubercles from the actinal surface. 



