294 .\NTHOPHYSIDAE. 



Anthophysidae Brandt, 1835. {Semu Haeckel). 

 Athorybiadae Huxley. 



In this family Haeckel ('88b) recognized four genera, Athorybia, Antho- 

 physa, Rhodophysa, and Melophysa. The last two, which were neither described 

 in detail nor figured, were each founded on a single specimen which was soon 

 lost; they are problematical. In the case of Melophysa Chun ('97b, p. 50) 

 has cut the Gordian knot by discarding it altogether. Rhodophysa can hardly 

 be treated in such a summary fashion, because of the supposed presence of rudi- 

 mentary swimming cavities on its bracts. But until the genus is re-examined 

 (if it ever is?) further discussion of it is futile. However, I may point out that 

 the name Rhodophysa was preoccupied by Blainville ('30) for the species earlier 

 described by Eschscholtz ('29) as Athorybia, a fact which Haeckel himself 

 recognized. 



Athorybia and Anthophysa are very well-marked genera. Schneider ('98), 

 it is true, united them on the supposition that the apparent absence of stem in 

 the latter is due to contraction. But my own examination of living, as well 

 as of preserved specimens of Anthophysa entirely supports the conclusions of 

 Chun ('97b), and Bedot (: 04) that not only the presence of two kinds of tentilla, 

 but especially the absence of any true stem, the absence of rudimentary swim- 

 ming bells, the peculiar arrangement of the bracts, and the internal structure 

 of the pneumatophore are sufficient to separate Anthophysa from Athorybia. 



The genus Athorybia, though long known, has seldom been recorded. 

 Chun ('97b) recognized two species: — A. melo (Quoy and Gaimard) with longi- 

 tudinal ribs on the outer surface of the bracts, and A. rosacea (Forskal) with 

 smooth bracts. But all recently recorded Athorybias are of the former type. 

 As pointed out by Schneider, the true explanation of the apparent difference 

 between the specimens, "A. heliantha," examined by Gegenbaur ('60) on the one 

 hand and Haeckel and Chun ('97) on the other, is that the nematocyst ribs are 

 very variable in prominence, just as they are in Anthophysa. Apart from this 

 very doubtful character, the various descriptions do not afford a single feature 

 to separate two species of Athorybia. Therefore they are all united here as 

 A. rosacea (Forskal) Eschscholtz (p. 349). 



The genus is also recorded from the Indian Ocean by Huxley ('59), and 

 from the Pacific by Fewkes ('89b) ; and so far as their figures show, there is no 

 difference between the Atlantic, the Pacific, or the Indian forms. But to settle 

 this question definitely will require a comparison of specimens. 



