136 BULLETIN OF THE 



stica of Philippi (Miiller's Arch., 1843). Leuckart thought (Siphonopkoren 

 vo)i Nizza, p. 106, note 2) that this species ought to be made a new- 

 genus. I have not found the form redescribed by any naturalist since 

 Phihppi, and, although I have frequently taken Pliysophora hydrostatica 

 and Fhilipin in my excursions on the Mediterranean, I have never seen 

 tetrastica. Gegenbaur's view, to which Keferstein and Ehlers also in- 

 cline {Zoologische Beitrdge, p. 30, note 7) seems a good explanation of the 

 apparently multiserial arrangement of nectocalyces spoken of by Philippi. 

 Gegenbaur suggests that this multiserial character of the necto-stem in 

 tetrastica is brought about by an accidental twisting of the necto-stem, a 

 thing which often happens in Physophora, Agalma, and Halistemma. An 

 Agalma which answers to Leuckart's description of A. clavatum was found 

 in such numbers as to give me almost a perfect series between it and 

 Agalma Sarsii. It was not possible, however, for me to raise the lat- 

 ter from the former, but the evidence which have mentioned seems 

 enough to prove the identity of the two. Glaus * has already made a 

 similar suggestion. I have frequently taken at Villefranche a Jellj^-fish 

 identical, I think, with that which has been described by Glaus as Hali- 

 stemma tergestinum, and by Metschnikoff as Stephanomia pictiim. A 

 description of this animal, which I had formerly thought new to science, 

 I had prepared without any intimation of the previous work of these 

 naturalists. S. pictum was taken by Metschnikoff from the same locality 

 ■where my studies were made. I think from the character of the ten- 

 tacular knobs that we have in this interesting Siphonophore a true Agal- 

 mopsis as I have limited the genus, or a Physophorid with an elongated 

 stem, no part of which is enlarged into a sac as in Physophora, and 

 which is furnished with only a biserial row of nectocalyces. In addi- 

 tion it has a tentacular knob possessing an involucrum and a single 

 filament. Metschnikoff's change of the Jelly-fish described by him, which 

 is probably the same, from the genus Halistemma, to which he at first 

 referred it, to the genus commonly known as Stephanomia, was well 

 made. 



The feature which distinguishes Agalmopsis (Stephanomia, Metsch.) 

 picta from Halistemma, together with those already mentioned, is the 

 position of the sexual organs (PI. I. figs. 1, 3, 6), and, less definitely, 

 the small size of the covering scales as compared with the nectocalyces. 

 The crimson and orange sexual organs in H. tergestinum, as Glaus 

 figures them, and as I have also observed, are clustered, both male and 

 female, at the base of a taster (PI. I. fig. 6), the male mounted on an 



* Zeitsch. f. Wiss. Zool., Bd. XII. p. 559. 



