38 DISCOVERY REPORTS 



Diplorybia Fewkes, 18886. 



Anthophysa Chun, 18976; Bedot, 1904; Bigelow, 191 \b (excl. synonymy); Totton, 1936; Leloup, 1941. 



Athorybia Garstang, 1946, pp. 135, 140, 141, 190; non i^rj, 167, 175 ( = Melophysa melo). 



Anthophysa Garstang, 1946, pp. 141, fig. 45; 142, 147, 148, 167, 168, 170, 171, 172, 175; non 190 ( = Melophysa melo). 



Brandt (1835) established a genus Anthophysa based on unpublished figures and a manuscript 

 description by Mertens. Haeckel (18886) said that he had seen these and made a few comments on 

 them, but his observations are not sufficiently critical to enable me to come to a certain conclusion 

 about the generic identity of A. rosea Brandt. As far as I can judge it is congeneric with Kolliker's 

 Athorybia rosacea, but not with Bigelow's (193 1) A. rosacea. The species described and figured by 

 Bigelow (191 1 b) as Anthophysa rosea is of the same genus as Forskal's Physsophora (sic) rosacea 

 and Kolliker's Athorybia rosacea. 



I hope that the selection of the lectotype of Athorybia will end this confusion of generic names. 



Athorybia rosacea (Forskal), 1775. (Plates I— III.) 



This Mediterranean species was figured in colour by Quoy & Gaimard in 1827 as Rhizophysa 

 heliantha, by Kolliker in 1853 b as Athorybia rosacea and again, probably, by Haeckel from the Canaries 

 in 18886 under the name of Athorybia ocellata. Bigelow (191 lb) gave a detailed description and 

 figures of it under the name Anthophysa rosea. Finally, Leloup (1941) gave us the latest summary 

 of our knowledge of this genus under the name Anthophysa Brandt, 1835, together with some notes on 

 a specimen from the Gulf of Guinea. Leloup also plotted the distribution of the species. His figs. A-C 

 (194 1, pi. 1) are of interest for they tend to question the significance of Bigelow's similar photographs 

 of a section of an alleged superior, gas-secreting, secondary ectoderm of the pneumatochone. In 

 Bigelow's fig. 1 (191 1 b, pi. 23) the thickened secondary ectoderm reaches right across the vault of the 

 pneumatosaccus, a condition unparalleled, as far as I know, in any Physonect. But the pneumato- 

 phore lies obliquely, and the section may have missed the apex of the pneumatosaccus. In Leloup's 

 figures the condition is more normal. Further work on this point is needed. I recently studied 

 Athorybia alive at Villefranche, where Sabine Baur made some excellent coloured sketches 1 of it. 

 The only species of this genus Athorybia is characterized by having a large air-sac that forms the 

 bulk of the specimen. It is half covered by what Fewkes called the hood. Haeckel called it the necto- 

 style or attachment of the bracts, which he claimed were used in swimming. There are no nectocalyces. 



Behaviour. Whilst I was aboard the launch belonging to the Station Zoologique at Villefranche 

 in May 1950 a living specimen, 12-14 mm. in diameter, was secured at about 9 a.m. after being 

 detected by the keen eyes of the mechanic, M. Raibaud, as an inconspicuous floating object ' a peine 

 rouge '. No specimens had been seen there in the last forty years. Observation soon showed that the 

 animal could ascend and descend at intervals in the jar of sea-water, which I protected from the sun 

 with a duster. Before sinking, with closed bracts, a number of small bubbles would appear amongst 

 the bracts, and be removed by their movement. It was not possible to locate the pore from which the 

 bubbles must have come, although my notes twice mention that they appeared to be released from the 

 lower or basal part of the pneumatocyst, but I now believe that they must have come from an apical 

 pore. After an interval of ten minutes the animal would begin slowly to leave the bottom of the jar 

 again, after intermittent closure of the bracts that caused a slight rise followed by a falling back. The 

 partially raised bracts were held motionless during ascent and not flapped in the manner described 

 by Kolliker, except that when about an inch from the surface they opened somewhat and closed 

 with a kick. This action had the effect of sending the animal downwards for an inch before rising again 



1 Mile Baur has generously allowed me, with Professor Portman's permission, to publish reproductions of these unfinished 

 drawings. I consider them of greater value as records than finished ones. 



