102 . DISCOVERY REPORTS 



specimen came from the Southern Indian Ocean (36 32' S. lat., long, unknown), so that the name of 



their species, if applicable at all, should be used for one that occurs there. 



From the official narrative of the ' Astrolabe ' expedition it is difficult to follow the track from Trinidad 

 Island 1 in the South Atlantic, round the Cape to Albany, Western Australia. On 3 September 1826 

 'Astrolabe's' position was 37 17' S. lat., 27 W. long. On 13 September it was decided to make for 

 Albany, and on 20 September she was following the parallel of St Paul Island in the South Indian 

 Ocean, six or eight miles to the northward of which she probably passed on 21 September. Albany 

 was reached on 7 October. As she met with particularly violent weather in the eastward passage of 

 the Indian Ocean it seems unlikely that any collecting was done there although sea-temperature records 

 were made. On the return journey the course taken was through Sunda Strait to Mauritius and 

 Reunion and down to the Cape. It seems therefore more probable that the latitude, 36 32' S., given 

 for the capture of the original ' G.' australis was where the ship's track cut this parallel, somewhere off 

 Algoa Bay, particularly as Quoy & Gaimard say that it was here and off Western Australia that plankton 

 was abundant in the Indian Ocean. 



An examination of hauls made by R.R.S. 'Discovery II' in this area, namely at Station 1567, 

 37 50' S., 35 47' E., and Station 1568, 34 48' S., 34 28' E., reveals the presence of at least three 

 species of 'Galetta' that systematists in general would report as 'G.' australis. The differences are 

 seen at once in the lamellae of the posterior nectophores, but it was only after completing this report 

 that I was able to discriminate between anterior nectophores. One type of posterior nectophore can 

 be distinguished by having a rounded, undivided lamella, as in the Mediterranean species ' G.' turgida. 

 The second has a thickened, notched lamella, as described below for ['G.'] Sulculeolaria angusta sp.n. 

 The third kind of posterior nectophore is similar in profile to that figured by Bigelow (191 ib, pi. 5, 

 fig. 9), and the lamella has the 'duplex curve', figured by Bigelow (191 lb, pi. 5, fig. 9 bis). This is the 

 well known and adequately figured ' G.' biloba (Sars), 1846 (see Text-figs. 49-51). Quoy & Gaimard's 

 (1834) figure of 'G.' australis might represent any one of the three. The absence of any indication of 

 a somatocyst from this old figure may or may not be significant. 



If given only the basal (articulating) end of a well-preserved posterior nectophore of 'G.' biloba, 

 ' G.' turgida or ' G.' angusta ' it would now be possible for a specialist to identify it. If the lamella was 

 in good shape too, any competent systematist could do so. 



Bigelow & Sears (1937) gave a key for the identification of the anterior nectophores of the 'australis' 

 group of ' Galetta '. My criticism of this is that Leloup's species meteori is more clearly related to 

 Lensia subtilis and should be excluded. ' Galetta ' chuni is now so well known that it gives no trouble. 

 'G.' turgida, common in the Adriatic, has a minute somatocyst and a divided 'basal wing' in the 

 anterior nectophore and a rounded one in the posterior. The posterior nectophores are very character- 

 istic, and each end exhibits characters that are very useful to the systematist. Bigelow & Sears (1937) 

 found the task of identification of posterior nectophores more difficult than that of the anterior ones. 



The morphological features of specimens attributed by various authors to this ' species ' australis, 

 and over which there has been some confusion, are as follows : The somatocyst of the anterior .or 

 superior nectophore may be minute or nearly as long as the 'mouth-plate' or lamella. The posterior 

 nectophore may have a comparatively ' broad baso-ventral sector ' when viewed laterally, or may be 

 long and slender, and may or may not have lateral, longitudinal ' wings '. The ' mouth-plate ' or 

 lamella of the posterior nectophore may be long or short ; notched, or have a ' duplex curve ', or be 

 convexly rounded at the end. 



Bigelow (191 1 b) is the authority for the use of the name australis in recent years, having provided 

 (pis. 5 and 6) both good photographs and not such good drawings of a species of ' Galetta ' bearing 



1 Position: 20° 30' S, 29 20' W. 



