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