TABLE OF CONTENTS. 
INTRODUCTORY NOTE 
ECHINONEUS CYCLOSTOMUS Lesxke 
THE OUTLINE OF THE AMBITUS. Plates 4, 5 
DEVELOPMENT OF THE CORONAL PLATES. Plates 6, 7, 13 
ORAL AND ANAL SYSTEMS. Plate 15 
THE ABACTINAL SYSTEM. Plate 14 
THE SPHAERIDIA. Plates 16, 17 
ARRANGEMENT OF THE TUBERCLES AND SCROBICULAR CIRCLES. Bia 24, 25 
THE PEDICELLARIAE. Plates 18-23; Plate 26, figs. 16-19, 30, 31; Plate 27, oe 12, pee 23, 24, 
35, 36, 43, 44 
THE SPICULES OF THE TUBE-FEET. " Plate 28, “Ass = 4. 
THE PERIPODIA. Plate 28, figs. 15-24 : 
THE spINEs. Plate 26, figs. 1-15, 20-29; Plate 27, Fes, 1- il, 14-29, 25-34, 37- 42 
THE LANTERN AND AURICLES. Plate 11, figs. 1, 2, 7, 8; Plate 12 . . : 
THE ALIMENTARY CANAL. Plates 8-10; Plate 11, figs. 8, 9 
MICROPETALON PURPUREUM A. Aaassiz ano H. L. Cuarx. Plates 29-31 . 
LIST OF SPECIMENS 
SYNONYMICAL LIST 
PLATES. 
41 
At 
46 
47 
49 
50 
51 
53 
57 
58 
59 
60 
61 
63 
65 
66 
