71 



,Nr. 8. Obelia sp. (Inaba 1890 Fig. 20. 21.) 



Trophosome. Stein 10 mm high, wavy, with constrictions at the points of curvature, peri- 

 sarc swollen and projecting directly below the constrictions and giving rise to a branch. There 

 are three or four distinct rings at the lovver end of each Joint of the stem. Hydrotheca 

 obconical in shape, a little longer than broad, with straight margin, stalk rather long, 

 consisting of four or five rings. 



Gonosome. Gonotheca somewhat thick, bottle-shaped, borne on the hydrorhiza or a.xils 

 of branches, with a short stalk consisting of two or three rings; bell of medusa very 

 shallow, umbrella-slmped. 



Colour. Transparent. 



Locality. North of Jogashima, ,Boneri', Sagami Sea; 0,5 m below surface, on ter- 

 minal branches of Sargassum. 



Date. Gouothecae found in January. 



This species resembles the preceding so closely, that it is difficult t« mention the 

 differences, which consist merely in the comparatively longer stem, slighter curvature, thin 

 perisarc, and thicker gonotheca. According to Hincks the gonotheca of 0. geniculata is 

 elongated with a broad upper part which becomes gradually narrower below, as represented 

 in Inaba fig. 18; but in this species, although the gonotheca is also elongated and narrow 

 below, the broadest part does not lie at the upper end but a little below it ; it is however 

 possible that it belongs to the second variety of Hincks. In the second variety of 0. geni- 

 culata the stem is not only comparatively long as in this sjjecies, but the curvatures are 

 also slight; moreover Allman's figures of 0. geniculata published in the Report of the 

 Challenger E.xpedition (1888) are very similar to my specimens. Some doubt inay be 

 left on this point. 



The luxuriant growth of this species is very remarkable; if one catches hold of the 

 terminal branches of Sargassum from the boat, it is rare that one does not get two or 

 three colonies of this species, although it is difficult to recognize them out of water, 

 owing to their transparency. 



The small medusae that come in surface tows in front of the Misaki Laboratory 

 belong to this species; they have shallow bell with hanging manubrium, and are like 

 urabrellas in shape. Sometimes the medusae can be seen swimming with the bell turned 

 inside out, and presenting a curious appearance. There are 4 radial canals; the ten- 

 tacles Vary from 24 to 48 in number according to the age; the manubrium is short and 

 has four lobes at the lower end of the raouth; in füll grown specimens there are four 

 ovarian sacs hanging down from the lower part of the radial canals." (Inaba 1890.) 



Gouothyraea longicyatha Thornely 1900. 



(Fig. 28.) 

 Nr. 1609, lC09a Sammlung Doflein. 



Gonothyraea longicyatha. Thornely 1900 p. 454 tab. 44 Kg. 4, 4 a. 



Eine ganze Anzahl reich verzweigter, bis 35 mm hoher, steriler Stöckchen. Trotz 

 des Mangels an Gonotheken ist diese Form leicht an ihren langen kegelförmigen Theken, 

 den merkwürdigen Doppelzähnen des Tliekenrandes und dem zusammengesetzten Stamm 



