PLATE LVIII. 
The Lettering is the same in all the Figures. 
ai. Primary interradial cords. 7. Basiradial ligament. 
ar. The secondary (radial) cords. 7b. Interbasal ligament. 
B. Basal plate. In. Limestone network in the perisome. 
ic. Bands of connective tissue in the body-cavity. | ls, Interarticular ligament of stem. 
ch. Cavities of the chambered organ. p. Pigment granules. 
ch’. Their downward prolongations into the stem R’, First radial. 
e. External epithelium. re, Rectum. 
Sg. Fore-gut. rp. Plug of calcareous tissue within the radial funnel. 
G. Gut. V. Central vascular axis of stem. 
ib. Intervisceral blood-vessel. X. Plexiform gland. 
Z. Interradial ligament. | 
Figs. 1-3. Pentacrinus pecorus, Wyv. Thoms. 
Diam. Page 
1. Horizontal section through the lower part of the calyx, showing 
the bifurcation of the primary interradial cords (a7) in 
the basals, : ; : ; : an 4 () 124 
2. Horizontal section through the lower part of the radial 
pentagon, showing the upward extensions of the cavities 
of the chambered organ (ch), : : . oo Sho 105 
3. The central part of a median vertical section through the calyx, 
showing the chambered organ and its connection with the 
vascular axis of the stem, E : : 1x40 104 
Fig. 4. PENTACRINUS NARESIANUS, 0. Sp. 
4. Portion of a horizontal section of the disk, showing the position 
of the plexiform gland (X) between the fore-gut and the 
rectum, . : : ; ; ; cee coe 101 
Figs. 5, 6. PROMACHOCRINUS KERGUELENSIS, 0. sp. 
5. Portion of a horizontal section of the disk, showing the plexi- 
form gland (X), . : : ih hes ss. SSE 101 
6. A similar section nearer the calyx, . : ; y x as 101 
