SYSTEMATIC AND BIOLOGICAL ACCOUNT 61 



Stem (? contracted). Air-sac oblong, 6x2 mm.; nectosome 14x2 mm.; siphosome 23 cm. long, 



4-6 mm. measured dorso-ventrally, 3-7 mm. side to side, very muscular, segmented. Gastrozooids and 



tentilla missing. Other appendages (not well preserved) in a ventral band 2-7-3-7 mm - wide. 



I take this opportunity to publish a second record of the capture of Marrus (Stephanomia) orthocanna 



Kramp by ' Scotia ' on 31 August 1951 in haul 688. Locality: 59 50' N., 1 1° 24' W., two loose necto- 



phores, which I have compared with type material. 

 The figured holotype of Marrus orthocannoides bears the Brit. Mus. (Nat. Hist.) Register No. 



1952. 11. 19. 4. 



Agalma elegans (Sars), 1846. 

 Agalmopsis sarsii Kolliker, 1S536. 

 I have found no adult specimens, not even loose nectophores, of this species amongst the 20,000 

 siphonophore specimens that I have examined from the Gulf of Aden, or from the Somali or Arabian 

 basins of the Indian Ocean. But in November 1950 and January 1951 'Manihine' took eighty-four 

 small nectophores at five stations in the Red Sea (16-17 January 195 1) at a distance of from 5 to 35 

 miles east of Sanganeb Lighthouse, off Port Sudan, where the temperature must have been about 

 21-5-22° C. Also 'Discovery II ' took a young specimen at Station 2906 in the Red Sea. It had two 

 gastrozooids (no tentilla are visible) and two nectophores 4 mm. in diameter, which I have compared 

 carefully with Mediterranean specimens (Text-fig. 24). The only other specimens that I have found 



Text-fig. 24. Side and upper views of nectophore of Agalma elegans from Villefranche, x 8. 



in the whole of the vast amount of ' Discovery ' material from the Indian or Atlantic Oceans were some 

 well-preserved young ones, of typical form taken at Station 273, differing in no way from those that 

 I have examined from Villefranche, the Celtic Sea (M.B.A. Plymouth 'Mackerel Cruises'), Valentia 

 harbour (E. T. Browne collection) and to the north-west of the British Isles ('Scotia' 1951, St. 683, 

 6o° 18' N., 12° 20' W.). I must mention that Bigelow's figure (191 ib; pi. 19, fig. 2) of a nectophore 

 does not perhaps give a very good idea of the typical form. In fact for years this figure misled me into 

 mis-identifying the juvenile nectophores of Agalma okenii, which have only one ridge on the lateral 

 facet (see p. 64) as those of A. elegans. I give this warning because Bigelow's famous report is 

 a standard reference work, and his figure is the only one likely to be used by planktonologists. Leuckart 

 (1854; pi. 12, fig. 22) illustrated well the characteristic dorsal view, and showed its difference from that 

 of Stephanomia rubra, which he illustrated on the same plate in fig. 12. Leuckart's drawing of the 



