76 



Fig. 28. 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; &, the.eudocyst; d, the tentacular corona 



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

 cum; g, the intestine. 



PI. III. 

 Fig. 13. Triopa incisa. 



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

 I, 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. 415. Dentalium 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. 



A specimen unusually strongly curved. 



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



tubes on the surface (extraneous parasitical body) and the terminal aperture 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. 



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



Fig. 1620. Yoldia obtusa. 



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

 cates the size). 



