SYSTEMATIC AND BIOLOGICAL ACCOUNT 39 



to rest at the surface. My desire to obtain sketches of the living animal, and then to anaesthetize 

 and preserve it for detailed examination, as well as my fear that it might become moribund and lose 

 all its bracts, forbade me to keep it under observation alive for more than two hours or so, but the 

 ascent and descent with contracted tentacles were repeated some half-dozen times after capture. 

 I watched the descent three times. When, finally, 7% magnesium chloride was added in three stages, 

 after drawing off most of the sea-water, a slow beating of the bracts, which opened out at once, was 

 seen for a long time. 



Cook's first voyage. Whilst examining the third volume of Sydney Parkinson's unpublished water- 

 colour drawings made during Captain Cook's first voyage, I came across a page of sketches of this 

 animal which is reproduced here (Pis. II— III) since so few figures exist. It was 'painted from life in 

 October 1768 between the tropicks', and appears to be the earliest record of the species. Perusal of 

 a photographic copy of Banks's MS. Journal shows that the specimen was probably taken, with 

 other invertebrates on 4 or 7 October, at a position which I estimate to have been about 9-1 2 N. 

 and 22-23 ° W. 



Haeckel's ocellus. Haeckel described near the tip of each palpon a red ocellus and figured it as if it 

 had a small lens. I was interested therefore to observe in some of the living palpons small cercariae. 

 The palpons had a pink spot, but none had a lens. It may be that Haeckel was deceived by the 

 appearance of cercariae into thinking that there was a lens associated with the pink spot. 



Anatomy. Haeckel claimed to have discovered, what he said previous observers had missed, the 

 true nature of Athorybia. However, it seems that even Haeckel did not make the correct interpretation 

 of its anatomy. My suspicion, gained from examining one or two better preserved specimens in the 

 British Museum (Nat. Hist.) Collection, that the line of budding gastrozooids was not strictly median- 

 ventral, as Haeckel had described it, but took a curved course from a 'kink' or 'hilum' at the upper 

 right-hand side, down to the lower left-hand one (Text-fig. 5E), was recently confirmed by the 

 examination of several more specimens taken by 'Discovery', 'Carnegie VII ' and by Beebe, as well 

 as of the Villefranche specimen, which is probably the most complete one to be found anywhere. 

 In young specimens the ovoid pneumatophore rises with long axis vertically above the protosiphon, 

 and its ventral side is covered by bracteal lamellae. There are, in a young specimen, in addition to the 

 large protosiphon, three or four secondary gastrozooids on the right-ventral side, the youngest bud 

 placed on a higher level. This arrangement is comparable with the stage at which the nectophores 

 first appear in a larval Nanomia bijuga (Text-fig. 3). There is a corona of bracts attached to the 

 'nectostyle', which projects above the ventral side of the pneumatophore. Below the bracts there is, 

 in an early stage, another corona of about six comparatively large palpons provided with palpacles, 

 although these simple tentacles cannot always be seen. Later, more buds of secondary gastrozooids 

 appear on the upper right-hand side, just in front of the nectostyle. In one full-grown specimen from 

 Bermuda, 13 mm. in length, I counted eighteen gastrozooids, including buds. They form a staggered 

 row, descending in a curved line running from the budding zone towards and round the left-hand side 

 of the basal area (Text-fig. 5 E), as in Physophora (Text-fig. 5 C). By the time that they have all appeared 

 the animal has ' toppled over ' to the ventral side (or end) so that the original vertical axis is now at an 

 angle, and the apex of the pneumatophore is nearly covered by the nectostyle. 



The gonopalpons are produced on both right and left sides, in an order that has not yet been 

 ascertained, and from each common, gonodendral stalk arise five or six palpons. In addition to the 

 secondary gastrozooids already mentioned there is usually, I think, another gastrozooid budded near 

 the protosiphon. The arrangement of the gastrozooids that I have described has not been noticed 

 before. It is extraordinarily interesting because it links Athorybia not only with other Brachystelia 

 (short-stemmed forms), especially Physophora but also with such Macrostelia as Nanomia bijuga. 



