Plate VII. 



Fig. i. Echinosigra (Pourtalesia) phiale, the sub-oral region of the test. ^/^ Not the same specimen 

 as that represented in PL VI. Figs, i 2, 7. The limitation of the ambnlacral plates IV. a. i. 

 b. i could not be made out quite distinctly, but 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 / 1 . 



3. Pourtalesia Jeffreysi, part of the stone canal with the axial organ. l6 / T . 



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

 genital organs of the right side, bent outwards. I / I . 



5. Echinosigra (Pourtalesia) paradaxa, the suboral region of the test. ^/^ 



6. Urechinus naresianus, female genital organs. */,. 



7. Echinosigra {Pourtalesia) phiale, apical system and adjoining parts of the test. 2I /i- 



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



wards in order to show the course of the stone canal. I / l . 



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



to be distinguished in the ocular or ambulacral plates. I ^/ I . 



- 10. Echinosigra (Pourtalesia) paradoxa, female genital organs, g, and stone canal, s. 10 / t . 

 -ii. Pourtalesia Jeffreysi, female genital organs. 2 / I . 



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



axial organ. 2 /i- 



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



position. Vj. 



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



position. The two siphones are distinct. '/,. 



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



show the two siphones. J /j. 



- 16. Echinosigra (Pourtalesiaj paradoxa, anterior end of the test, opened from the side. g. Male 



genital organs, s. stone canal, oe. oesophagus. 6 /,. 



17. Spatagocystis Challengeri, tube foot. "S/!. 



- 18. Echinosigra (Pourtalesia) paradoxa, tube foot. I2 5/ r . 



19. Plexechinus hirsutiis, actinostome and surrounding parts of the test. The plates of the actino- 



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

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

 made out 8 /!. 



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



plate a small madreporic pore and two large* genital pores are seen. 'S/j. 



- 21. Pourtalesia Jeffreysi, tube-foot w/,. 



