No abstract

In the Bulletin series, the first of which was issued in 1875, appear longer, separate publications consisting of monographs (occasionally in several parts) and volumes in which are collected works on related subjects. Bnlletins are either octavo or quarto in size, depending on the needs of the presentation.Since 1902, papers relating to the botanical collections of the

While the first author had been engaged for years in the studies of the comparative anatomy of the circulatory system and in the cytological researches of the heart of Ciona, he became aware of a very strange fact. Specimens of Ciona for his works were first collected from the rafts in the oyster farm of the Oyster Institute in Mone Inlet ofKarakuwa-tyo, Miyagi Prefecture in the northeastern district ofHonsyu Island. And he found two types of Ciona in his material from this locality. The one has the test which is very soft as usually known for cosmopolitan Ciona intestinalis (L.) and quite free from any foreign materials on the surface, and its mantle is more or less sprinkled with orange pigment spots, especially densely near the tip of siphons. The test of the other type is, however, much thicker and harder and sometimes even harbours other organisms on the surface; its mantle is scarcely pigmented. Moreover, it was found that the two types differ from each other markedly not only in the feature of the test but also in the formation of the endostylar appendage and in the arrangement of the epicardia and pharyngo-epicardiac openings as shown later. For the operation to remove the test and body wall on the right side to expose or take out the live heart, the soft Ciona is much more suitable than the robust Ciona, while in the robust Ciona the body contraction caused by external stimuli is much less than in the soft Ciona, because the contraction is much checked by the existence of the thick and hard test regardless the sensitivity and contractility of the mantle itself. Thus, the robust Ciona is much better for the pigment injection into the blood vessels under anesthetization by menthol. To secure these two types of Ciona for respective operations, Ciona in another locality, the fish rearing tanks of the Onagawa Fisheries Laboratory ofTohoku University, was examined, and it was found that there most of Ciona were of the robust type. I) Contributions from the Seto Marine Biological Laboratory, No. 473.

I have already shown an idea of the taxonomical outline of Chaetognatha in the preceding volume of this journal (XII, No. 5, 1965, pp. 335-357); there it is stated that the pelagic forms of a simpler body structure seem to be derived from the littoral forms with creeping ability and with more complicated body structures and that the existence of the ventral transverse musculature is regarded as a basic feature separating the primitive forms from the advanced ones and the tooth apparatus of Krohnitta is considered to be a sign showing a high grade of specialization (p. 341), but no further reasons being given for such considerations. On the other hand, I gained a copy of Mrs. ALVARr:No's very important paper, "Quetognatos epiplanctonicos del Mar de Cortes" (Revista de la Sociedad Maxicana de Historia Natural, XXIV, 1963, pp. 97-203), after my manuscript had been laid under editorship; her opinion of grouping the species of Sagitta according to their morphological similarities or ecological affinities (pp. 136-141) is to be appreciated very highly, but the comparison between hers and mine was not made in my last paper. The present paper is prepared to make up for the above-mentioned insufficiency. *9. Eukrohnia hamata *10. Eukrohnia fowleri *11. Eukrohnia bathyantarcti~a *12. Eukrohnia bathypelagica *13. Heterokrohnia mirabilis *14. Bathyspadella edentata 15. Sagitta bipunctata **16. Sagitta setosa **17. Sagitta setosa var. euxina **18. Sagitta tenuis **19. Sagitta jriderici 20. Sagitta helenae **21. Sagitta bombayensis **22. Zonosagitta bedoti **23. Zonosagitta bedoti f. minor **24. Zonosagitta bedoti f. littoralis 25. Zonosagitta pulchra 26. Serratosagitta serratodentata 27. Serratosagitta pesudo-serratodentata ***28. Serratosagitta tasmanica ***29. Serratosagitta bierii 30. Serratosagitta pacifica **31. Parasagitta elegans **32. Parasagitta elegans arctica **33. Parasagitta elegans baltica **34. Parasagitta hispida **35. Parasagitta hispida americana 36. Parasagitta robusta 37. Parasagitta ferox

Species common to the Japanese waters and the Pacific coasts of North America. *25. Dendrodoa pulchella *26. Pelonaia corrugata 27. Pyura mirabilis *28. Boltenia ovifera *29. Boltenia echinata *30. Halocynthia aurantium (*)31. Halocynthia hilgendorfi f. igaboja *32. Eugyrioides glutinans *33. Pareugyrioides dalli *34. Molgula griffithsii *35. Molgula retortiformis *36. Molgula pugetiensis *37. Rhizomolgula globularis