86 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
PLATE XII. 
Fig. 1. Phrissocystis aculeata A. Ag., apical part of test. 
Fig. 2. Phrissocystis aculeata A. Ag., odd interambulacral area. 
Fig. 8. Phrissocystis aculeata A. Ag., odd ambulacrum. 
Fig. 4. Phrissocystis aculeata A. Ag., left posterior ambulacrum. 
Fig. 5. Phrissocystis aculeata A. Ag., part of left side of test. 
Fig. 6. Phrissocystis aculeata A. Ag., anal system. 
Fig. 7. Phrissocystis aculeata A. Ag., actinal system. 
Figs. 1-7 natural size. 
Fig. 8. Fasciole of Spatagodesma. . 
PLATE XIII. 
Fig. 1. Echinocrepis setigera A. Ag., apical part of test. 
Fig. 2. Echinocrepis setigera A. Ag., odd anterior ambulacrum from above. 
Fig. 8. Echinocrepis setigera A. Ag., odd anterior ambulacrum from below. 
Fig. 4. Echinocrepis setigera A. Ag., posterior interambulacrum from above. . 
Fig. 5. Echinocrepis setigera A. Ag., anal proboscis in profile. 
Fig. 6. Echinocrepis setigera A. Ag., anal system from below. 
All figures natural size. 
PLATE A. 
CHART SHOWING THE TRACK OF THE “ ALBATROSS.” 
