Gehould. — Caudina. 
Fig. 51. 
Fig. 52. 
Fig. 53. 
Fig. 54. 
Fig. 55. 
Fig. 56. 
Fig. 57. 
Fig. 58. 
Fig. 59. 
Fig. 60. 
Fig. 61. 
Fig. 62. 
Fig. 63. 
Fig. 64. 
Fig. 65. 
Fig. 66. 
Fig. 67. 
Fig. 68. 
Fig. 69. 
Fig. 70. 
Fig. 71. 
Fig. 72. 
PLATE 5. 
For abbreviations see Explanation of Plates, p. 73. 
Cross section through the pharynx, showing the inner epithelium. 
X 500. 
Cross section through the stomach showing inner epithelium and 
connective tissue. X 500. 
Cross section through the stomach of Cucumaria frondosa. X 40. 
Longitudinal section through the wall of the small intestine of 
Caudina. X 500. 
Cell from the inner epithelium of small intestine. Maceration prepa¬ 
ration. X 500. 
Peritoneal epithelium from the wall of the stomach. X 280. 
Epithelium from the mesentery of the intestine. Silver-nitrate prepa¬ 
ration. X 280. 
Section of the wall of the respiratory tree. X 420. 
Peritoneal epithelium from the respiratory tree. X 280. 
Brown spheruliferous corpuscle from the large intestine. X 500. 
Cross section of large intestine showing external longitudinal muscle 
bands., X 24. 
Section through the inner epithelium of the cloaca. X 280. 
Connective-tissue cell from the mesentery of the small intestine. 
X 500. 
Interradial plate of calcareous ring; a, external; 5, internal face. 
Radial plate: a, edge view; 6, exterior view; c, viewed from within 
the calcareous ring. 
Aquapharyngeal bulb seen from the left side. X 2. 
Diagram of the branches of the median-ventral radial water canal 
to the tentacles. View from within the aquapharyngeal bulb. 
Branches graphically reconstructed from a series of sections. 
Posterior face of a cross section through aquapharyngeal bulb show¬ 
ing the openings of the radial canals into the circular canal. 
Posterior face of a section through the aquapharyngeal bulb, further 
forward than the last. 
Similar view of a section still further forward, where the radial and 
interradial plates form a continuous ring. 
Portion of posterior face of a cross section further forward showing 
the opening of the two lateral branches of the median-ventral canal 
into the tentacles. 
Portion of posterior face of cross section showing the origin, from 
the radial canal, of the tentacular canal ( aq . ta .') which unites with 
the adjacent (median-ventral) tentacle. In this case the tentacular 
branch arises on the left side of the radial canal. 
