536 THE FUR SEALS OF THE PRIBILOF ISLANDS. 



Fig. 13. Branchial tentacles of same. 



Fig. 14. Colony of Polyclinum globosum, with a portion cut away. The, small area at /? indicates 



about the distribution of the zooids, and shows the branchial orifices, though much more 



distinctly than they can actually be seen. 

 Fig. 15. A single zooid of same species. 

 Fig. 16. Atrial languet of same, seen from the under side. 

 Figs. 17 A. and 17B. Two sectioned colonies of Polyclinum pannosam, 17A showing the zooids in their 



normal form and position, and 17B the degenerated zooids. I'lio characteristic ragged 



surface of the colony is shown at y, 17B. 

 Fig. 18. Portion of a zooid of P. pannosum. 

 Fig. 19. A colony of ApHdiopsis jordani with an individual of Dendrodoa subpedunciilala, D. S., imbedded 



in it. 

 Fig. 20. A zooid of A. Jordani. The post-abdomen outlined in this specimen is unusually short. 

 Pigs. 21, 21A, and 21B. Portions of different zooids of Amaroucium Mncaidi. 21A and 21B drawn par- 

 ticularly to show the equivocal character of the irregularities in the stomach walls. 

 Fig. 22. A colony of Amaroucium snodgrassi. The specimen is seen from its base, B, and one of its 



precipitous edges, on which latter the zooids z are visible through the semitransparent test. 

 Fig. 23. Stomach and small portion of intestinal loop of Amaroucium snodgrassi. 

 Fig. 23A. Anterior end of zooid of same species, seen from inside. 

 Fig. 23B. A few of the remarkably long, narrow stigmata of same species. 

 Fig. 24. A colony of Amaroucium priMlovense. 



Fig. 25. A single zooid, the posterior part of the post-abdomen wanting, of the same species. 

 Fig. 26. A colony of Synoicum, irregulare. 

 Fig. 27. The cut surface of one of the lobes of a colony of same species, showing the packages of 



embryos, e, imbedded in the test. 

 Fig. 28. A zooid of S. irregulare. 



Plate LXXXVI. 



Figs. 29, 29a, and 296. Ovarian ova of S. irregulare, 29 and 29b containing ingested cells. X 360. 



Fig. 30. An ovarian ovum, presumably nearly ready for maturation. X 360. 



Fig. 31. Two-celled stage. X 360. 



Fig. 32. Morula? early gastrula stage, x 360. 



Fig. 33. Embryo well advanced in metamorphosis. This from one of the cavities containing embryos 

 only. X 40. 



Fig. 34. Small portion of the test of an old embryo. The cellular masses, x, are the same as the 

 bodies shown at x, fig. 33. These probably belong to the test of the embryo itself. The 

 mass y. Tc. is imbedded in the test, and is without doubt a cluster of the mesenohymatous 

 yolk containing bodies found in the parental post-abdomen, m. /. appear to be muscle 

 fibers derived from the mantle of the parent. 



BIBLIOGRAPHY. 



BONNEVIE, KRISTINE. 



1896. Ascidiae Simplices og Ascidiae Compositae. Den Norske Nordhavs-Expedition, 1876-1878. 

 XXIIl, Zoologi. 

 Edwakds, Milne. 



1846. Observations sur les ascidies compos6es des C6tes de la Manche. M(5moire8 de I'Acaddmie 

 royale des sciences de I'Institute de France. T. XVIII, 1846. 

 GlARD, A. 



1872. Recherches sur les Ascidies composdes, ou Syuascidies. Thfeses, 1872. 

 Hancock, Albany. 



1868. On the Anatomy and Physiology of the Tunicata. Journal Linneau Society— Zoology. 

 Vol. IX, 1868. 

 Heller, Causil. 



1877. Untersuchungen iiber die Tunicaten des Adriatischen und Mittelmeeres. Ill (1) Abtheil- 

 ung. Denksohriften d. kais. Akad. d. Wissensch. Wien, Math.-naturwiss. Classe. Bd. XXXVII, 

 1877. 



