720 MEDUSA OF THE WORLD. 



HYDROMEDUSjE. 



Maas, 1909 (Abhandl. Math. ph^s. Klasse der K. Bayer. Akad. der Wissenschaft, Miin- 

 chen, Suppl. Bd. i, Abhandl. 8), gives a description of 23 hydromedusx from Japan obtained 

 upon Doflein's vo\age. 



The old species are Cytais vulgaris. Tiara papua, Prohoscidactyla fiaviclrrata var. stoloni- 

 jera, S pirocoJon saltatrix, Eucheilota paradoxica, Plitohdiiint pacifictini, Plualtdiutn Jiscoida, 

 Mesonema pensile, Gonionemus vertens var. depressutti, Olindioides formosa, Liriope rosacea, 

 Rhopalonema velatum, Aglaura hemtstoma, /Egina rosea, Solmundella bitentaculata, Cunina 

 peregrina, and Solmaris rliodoloma. 



The new forms are called Sarsia japonica, Nemopsis dofleint, Turritopsis nutricula var. 

 pactfica, and If illsia pacifica. A Zanclea and an Ohelia are possibl\- new. 



It is interesting that Eucheilota paradoxua, known hitherto only from the Florida-Bahama 

 region, should be reported from Japan. 



One of the most valuable features ot Maas's paper is his redescription, accompanied by an 

 excellent account of the post-embryonic development of Spirocodoii saltatrix. Reviews of his 

 account of this, and of the new forms, are presented in this Appendix. 



An important paper upon Arctic Hydromedusae and Sc\phomedusaB is that of Hartlaub, 

 1909, Croisiere Oceanographique Belgica dans la Mer du Gronland, Meduses, 18 pp., planches 

 76-77. Unfortunateh' this has reached me too late to be reviewed for this work. 



Pennaria tiarella (see page 25, Vol. I). 

 Pennaria tiarella, Harcutt, G. T., 1909, Bull. Mus. Comp. Zool. at Harvard College, vol. 53, p. 164, 5 plates, 44 figs. 



Hargift studies the development of Pennaria tiarella and finds that the oocyte nucleus 

 dissolves within the germinative vesicle before the nuclear membrane is ruptured. The linine 

 network of the germinative vesicle extends to the nucleolus, so that an interchange of substances 

 may possibl)' occur between the chromatin and the nucleolus. 



The two polar bodies appear to be formed at about the time of the liberation of the medusa, 

 by a process of mitosis of which Hargitt gives a detailed account. 



Fertilization usually occurs after the polar bodies have been formed. The cytoplasm is 

 very active at this time, forming protuberances upon the surface of the egg. The male and 

 female pronuclei unite by apposition. 



The first cleavage spindle seems to form from the cytoplasm. The cytoplasmic division 

 is delayed, the second nuclear division being completed before the first cleavage furrow has 

 cut half through the egg. 



Hargitt disagrees with Bcckwith, 1909, and finds that the polar bodies are seen onlv at or 

 near the time of the liberation of the medusas, about 7 p. m. He also finds, contrary to Bcck- 

 with, that the nucleolus disappears within the germinative vesicle before the dissolution of the 

 nuclear membrane, whereas Beckwith states that it is cast out into the c\toplasm. 



Corymorpha nutans (see page 31, Vol. I). 



Corymorpha nutani, MaIj\rd, 1907, Bull. Museum Paris, p. 563. — Torrey, 1907, Science, vol. 25, p. 734. 



Malard finds Corymorpha nutans when dredging in deep water northeast of the He Tati- 

 hou, coast of France, and Torrey observes spontaneous fission in the stems of the hydroid. 



Sarsia rosaria (see page 59, Vol. I). 

 Santa rosaria, Kishinouyf, 1910, Journ. College of Sci., Tokyo, vol. 27, art. 9, p. 24. 



Kishinou)e finds this medusa off the Kurile Islands, north of Japan. A. Agassiz records 

 it from the Pacific coast of North America. 



Sarsia japonica Maas. 

 Sarsia japonica, Maas, 1909, Abhandl. Akad. Wissen., Miinchen, Suppl. Bd. i, Abhandl. 8, p. 6, taf. i, fig. i. 



Bell 12 to 15 mm. high, 4 to 6 mm. wide, with flatly rounded apex. Bell wails 2 mm. 

 thick. Manubrium nearly c\iindrical, four-fifths to five-sixths as long as the depth of the bell- 

 cavity. Gonads scattered irregularly over the manubrium from the base to near the mouth. 



