Plate VII. 



Fig. I. Echmosigra (Pourtalesia) phiale, the sub-oral region of the test. '3/,. Not the same specimen 

 as that represented in PI. VI. Figs. i — 2, 7. The limitation of the ambulacral piates IV. a. i. 

 b. I could not be made out quite distinctly, bift it is certain that a. i was larger than b. i. 



— 2. Pourtalesia Jeffreysi, opened from the side. The loop of the intestine has been bent backwards 



in order to show the course of the stone canal. g. Genital organs, '/i. 



— 3. Pourtalesia Jeffreysi, part of the stone canal with the axial organ. 'Vi. 



— 4. — — opened from the side, showing the intestine in its natural position; g. the 



genital organs of the right side, bent outwards. '/i- 



— 5. Echinosigra (Po2irtalesia) paradoxa, the suboral region of the test. '3/i. 



— 6. Urechinus naresianus, female genital organs, ^/i. 



— 7. Echinosigra ( Pojirtalesia) phiale, apical system and adjoining parts of the test. ^i/,. 



— 8. Urechinus naresiamis. opened from the side. The loop of the intestine has been bent back- 



wards in order to show the course of the stone canal. '/j. 



— 9. Plexechinus hirsutus, apical region of the test. From a specimen 6""" in diameter. No pores 



to be distinguished in the ocular or ambulacral piates. 's/j. 



— 10. Echinosigra (Pourtalesia) paradoxa, female genital organs, g, and stone canal, s. i°/i. 



— II. Pourtalesia Jeffreysi. female genital organs, ^/i. 



— 12. — — male genital organs. On the stone canal (s) is seen a little swelling, the 



axial organ, ^i- 



— 13. Urechinus naresianus, opened from the abactinal side; the intestine is represented in its natural 



position, i/j. 



— 14. Pourtalesia Jeffreysi, opened from the actinal side ; the intestine is represented in its natural 



position. The two siphones are distinct. 7i. 



— 15. Urechinus naresianus, opened from the abactinal side. The intestine bent aside in order to 



show the two siphones. '/i- 



— 16. Eciiinosigra (Pourtalesia) paradoxa, anterior end of the test, opened from the side. g. Male 



genital organs, s. stone canal, æ. oesophagus. ^i- 



— 17. Spatagocystis Challengeri, tube foot. "5/j. 



— 18. Echinosigra {Pourtalesia} paradoxa, tube foot. '^s/^, 



— 19. Plexechinus hirsutus, actinostome and surrounding parts of the test. The piates of the actino- 



stome have been drawn from another specimen; the specimen, from which the piates of the 

 test were drawn, had the buccal membrane bent inwards, so that its piates could not be 

 made out. 7i- 



— 20. Plexechinus hirsutus, apical plate and part of the odd anterior ambulacrum. In the apical 



plate a small madreporic pore and two larger genital pores are seen. '5/,. 



— 21. Pourtalesia Jeffreysi, tube-f oot. '75/^. 



