166 CEYLON PEARL OYSTER REPORT. 



PLATE IV. 



Figs. 1 to 6. Solmundella bitenfaculala. 



Fig 1. Transverse section of the peronium (P.) in the radius without tentacles, also showing the gastric 

 pouches (Stp.) and the gonads (G.). x 260. 

 2. Transverse section of the peronium (P.) in the radius with tentacles, showing the peronial 



groove (P. G.) x 270. 

 3. Transverse section across the gastric pouches (Sip.), showing the position of the peronium (P.) 



in the radius without tentacles, x 20. 

 4. Transverse section of a tentacle not far from the base, x 100. 

 5. Longitudinal section of a portion of a tentacle not far from the distal end. x 270. 

 6. Sketch showing the peronium (P.) running from the margin of the umbrella to the tentacle. 

 * Plane of section, fig. 2. ** Plane of section, fig. 4. 

 Fis;s. 7 to 11. Laodke indica, n. sp. 

 Fig. 7. Longitudinal section of a cordylus. x 350. 



8. Longitudinal section through the basal bulb of a tentacle, x 150. 



9. Tentacle, cirrus, and cordylus. Inner view, x 85. 



10. Transverse section of an ovary, showing the escape of an ovum, x 80. 



11. Terminal cluster of nematocysts of a cirrus, x 380. 



12. Cytceis herdmani, n. sp. Transverse section of a tentacle, showing the nematocysts in the 

 ectoderm and the pigment granules in the endoderm. x 40. 



