76 



Fig. 38. The end of a living colony, somewhat more strongly magnified, a, a greatly ex- 

 tended avicularium; b, a polypide fully extended. 



— 29. The mandible of an avicularium seen from the inner or concave side. 



— 30. A polypide with its cell, a, the ectocyst; b, the endocyst; d, the tentacular corona 



(the lophophore with its tentacles); c, the oesophagus; f, the stomach with its cae- 

 cum ; (f, the intestine. 



' PI. III. 



Fig. 1—3. Triopa incisa. 



Fig. 1. A specimen seen from above, about 6 times magnified, a. a, the dorsal tentacles; 

 h, the anus with the rudimentary gills. 



— 2. The same seen from the right side, a, the dorsal tentacle; c, the genital porus. 



— 3. The same seen from below. 



Fig. 4 — 15. Deiitaliiun agile. 



Fig. 4. The largest specimen found (the annexed line indicates the natural size), seen from 

 the right side. 



— 5. A smaller specimen with evident longitudinal striation in the posterior part of 



the* shell. 



— 6. A specimen unusually strongly curved. 



— 7. The extremity of a specimen viewed from below, shewing the peculiarly ramified 



tubes on the surface (extraneous parasitical body) and the terminal apei'ture'with 

 the protruding supplementary tube. 



— 8. The same part seen from the left side. 



— 9. A piece of the shell strongly magnified, shewing the anterior ramifications of the 



superficial parasitical body. 



— 10. A living specimen seen from the right side, with extended foot and captacula. 



— 11. The anterior extremity of the shell, with the part of the mantle extended beyond 



the aperture, the foot and captacula; more strongly magnified. 



— 12. The posterior spade-shaped appendage seen from the right side. 



— 13. The same viewed from below. 



— 14. A particularly small specimen, shewing the smooth embryonic shell corrugated 



transversely. 



— 1.5. The extremity of the same viewed from above, more strongly-magnified. 



Fig. 16—20. Yoldia obtusa. 



Fig. 16. A perfect specimen viewed from above, slightly magnified (the annexed line indi- 

 cates the size). 



