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



Pourtalesia lagmicula, A. Ag. (figs. 7-15), p. 137. 



7. Seen in profile, denuded (f ). 

 Same, seen from the actinal end. 

 Same, seen from the actinal side. 

 Interior view of the abactinal system. 



Three interambulacral plates from the median part of the test. 

 Interior view of anterior jjart of test, to show Hoffman's organ. 

 Interior view of anal extremity of test. 

 One of cluster of genital organs. 



PLATE XXIII. 



Cionobrissus revinctus, A. Ag. (figs.1-12), p. 188. 



Fig. 1. Seen in profile denuded; natural size. 



,, 2. Seen from the abactinal side, covered with spines. 



„ 3. Same, seen from the actinal side. 



„ 4. Same as fig. 1, seen facing the anal extremity. 



,, 5. Same as fig. 1, seen facing the anterior extremity. 



,, 6. Petals and surrounding peripetalous fasciole. 



„ 7. Magnified view of posterior extremity, seen in profile. 



,, 8. Interior view of actinostome. 



„ 9. Exterior view of actinostome denuded. 



, , 10. Profile view of course of alimentary canal. 



,, 11. Actinal view of same. 



„ 1 2. Abactinal view of same. 



PLATE XXIV. 



Homokmipas fulva, A. Ag. (figs. 1-12), p. 164. 



Fig. 1. Seen in profile, denuded ; natural size. 



2. Same, seen from the abactinal side, one-half of test covered with spines. 



3. Same, seen from the actinal side. 



4. Enlarged view of posterior extremity, showing anal system and subanal fasciole. 



5. Interior of anal part of test, showing termination of alimentary canal. 



6. Interior view of apical system, sho'ndng the four ovaries. 



7. Interior view of apical system, showing the four genital openings. 



