10 DISCOVERY REPORTS 



me to conclude that Sulculeolaria quadridentata is identical with S. quadrivalvis (see Systematic Notes, 

 p. 109). 



Finally, I have picked out thirty-three species of Siphonophores from ten of the stations made in 

 1950-1 by ' Discovery II ' along a line in longitude 90 E. The finding at Station 2895 in surface waters 

 of Sulculeolaria biloba led to a long-needed revision of the old genus Galetta and its submergence in 

 Sulculeolaria. 



It is comparatively easy to preserve Siphonophora in good condition for morphological work, if not 

 for exhibition. They can be engulfed at the surface of a calm sea in a bottle, or picked out with a dip- 

 net, and they should be isolated unless very small. Two or three or more live specimens of a species 

 such as Rosacea cymbiformis, if kept in ajar, soon become inextricably entangled. The use of an isotonic 



Chart. Stations in the Gulf of Aden occupied by 'Mabahiss', 'Discovery II' and Mr Fraser-Brunner. 



solution of magnesium chloride makes it possible to achieve a good deal of relaxation of muscles and 

 consequent expansion before killing in formalin, which should contain at least 5 % formaldehyde. 

 It is advisable to add 2 lb. of hexamine (hexamethylenetetramine) to each gallon of 38-40 % formalde- 

 hyde solution to buffer it. Before subsequent examination it is a good plan to stain for a day or two 

 with dilute Grenacher's Borax-carmine. A little of this stain can be added to the jar in which the 

 specimens are preserved. For examination of the external form of nectophores and bracts, brief 

 staining in dilute Delafield's haematoxylin is effective, but if hexamine has been used the specimens 

 must first be thoroughly washed or the stain will be precipitated. 



To photograph them alive is exceedingly difficult because of the lack of contrast, the depth of the 

 field that it is necessary to cover, and their constant change of form and position. 



The text-figures, with the exception of a few diagrammatic ones, were all drawn by the author with 

 the aid of a camera lucida. The inking in of the figures was done by Mrs Walker (ne'e E. C. Humphreys) 

 after demonstration and examination of the specimens. A subsequent check with the specimens was 

 made by myself, or by both of us. In order to be able to make drawings of large specimens I removed 

 the foot of a Leitz binocular and made the stage slide on a track, fixed at such a height above the 



