138 BULLETIN OF THE 



The pigment spots mentioned in the nectocalyx of Agalmopsis picta 

 have no resemblance to these peculiar bodies on the bracts, nor do they 

 change their color when the swimming-bell is detached. The presence 

 of such spots on the younger bell oi Agalmopsis picta, and so little devel- 

 oped on the adult, rank them among patterns of embryonic coloration, 

 examples of which are not unknown on other structures of these animals. 

 Stephanomia * [Forskalia) has a similar large yellow spot, which persists 

 in the adult nectocalyx, at the junction of radial and circular tubes. 



The diiferent stages in development of the female sexual organs of 

 Halistemma have never been described or figured. Kolliker,! in his 

 plate illustrating this genus, does not even represent these parts, and 

 Leuckart J figures the female organs as a botryoidal structure, at the apex 

 of a single polyp-like stalk. In several specimens, in addition to a struc- 

 ture of this kind, we have, as I have figured (Plate II. Fig. 3), others 

 with the stalk on which the botryoidal mass is borne bifid at its extrem- 

 ity. This is probably simply another stage in development of these 

 organs. As Leuckart well says, the sexual organs in Halistemma have 

 no direct connection with the tasters; still, the female structures, at 

 times, arise very near them.§ 



* The single yellow pigment spot at the junction of radial and circular tubes in 

 Stephanomia (Forskalia) has on each side a finger-like process, and also, separated 

 from these only by a short distance, an additional pair of the same rudimentary ten- 

 tacles, as they may be called. The pigment spot is mentioned by Kolliker, who also 

 calls attention to one pair of these tentacles or processes. He says : * ' Der Pigment- 

 fleck ist insofern interessant als bei keinerandcrii Siphonophore Pigmentirungen de 

 Schwimmglocken beobactet wurden." (Schwimmpolypen von Messina, p. 4.) 



t Kolhker, Schwimmpolypen von Messina, Tab. IV. 



X Leuckart, Zoologische Untersuchungen, Tab. II. fig. 14 ; Siphonophoren von 

 Nizza, Tab. XII. fig. 15. 



§ Glaus says {E. Tergestioium, &c., p. 45) : *' Wo man bei verwandten Agalmiden 

 die Sprossung der Gesclilechts-traubchen am Stamme beschreiben iindet representirt 

 entweder der Stiel des Traubchens einen Taster dessen Endabschnitt kurz und ver- 

 kiimmert bleibt oder aber der Tasterschlauch hat sich von Stiele gelost und ist abgefal- 

 len. " The resemblance to a taster of the stalk upon which the botryoidal female organs 

 of Halistemma are borne, is very small. However, in Agahnopsis and Stephanomia 

 {Forskalia) we find the sexual system at the base of the true taster, which seems to 

 support Claus's suggestion. Huxley, who had not seen the genus Halistemma when 

 " Oceanic Hydrozoa " was written, says of reproductive organs that they are like those 

 of Stephanomia, and are attached directly to the coenosarc. The sexual organs have 

 no similarity in point of attachment, as can be seen from my figures of these two 

 genera (PI. 11. figs. 1, 3) ; for while in the case of Halistemma they arise directly 

 from the stem, in Agalmopisis [Stephanomia) they are united to the base of the taster. 



