56 ALLMAN. — USE OF THE TOWING NET. 



like series of transparent, gelatinous, variously shaped bodies, 

 frequently ornamented with spots of bright colour, scarlet or 

 orange. They may be easily detected swimming with a rhythmical 

 repetition of impulses near the surface of the sea. They require 

 great care in their capture, being formed of numerous zooids or 

 more or less independent buds, which by rough handling are 

 easily separated from one another. Though less easily broken to 

 pieces than some other groups of associated zooids, such as the 

 chains of Salpse, to be presently referred to, those taken in the 

 towing net will often be found injured, and a perforated or brass 

 wire gauze ladle slipt under them while swimming will generally 

 be found the best way of removing them from the sea. Here 

 again drawings ought to be made when possible, as no known 

 method of preservation will satisfactorily retain their characters. 

 The best is that above recommended for the Hydroid Medusae. 

 Other forms of Siphonophora, such as Physalia (Portuguese Man 

 of War), Velella and P or pita, obtained abundantly in the more 

 equatorial latitudes, have firm supports of the soft parts, and are 

 therefore much more easily preserved. None of these have yet 

 been taken in Arctic seas. They are best preserved by being 

 placed in methylated spirit. 



The Discophorous Medusce present a general resemblance to 

 the Hydroid Medusas in their gelatinous umbrella-shaped swim- 

 ming disc, by the rhythmical contraction of which they impel 

 themselves through the sea. They attain, however, for the most 

 part a much larger size. The smaller forms may be treated as 

 has been recommended for the preservation of the Hydroid 

 Medusse and Siphonophora ; but we should scarcely recommend 

 any attempt to preserve the larger ones, which frequently attain a 

 diameter of one or more feet, and which would need (to obtain at 

 best very unsatisfactory results) more preserving liquid and space 

 than could be afforded them. Here again the aid of the draughts- 

 man is indispensable. 



Both Hydroid and Discophorous MedussD are commonly known 

 by the name of "jelly fish." The observations of Scoresby and 

 of the naturalists attached to Kotzebue's voyages have proved 

 that both forms abound in high latitudes. 



The Ctenophora {Beroe, Cydippe, &c.) form a large part of the 

 surface life of the sea. They are often of considerable size, are 

 constant products of the towing net, and ought to be preserved in 

 the way indicated for the Medusse and Siphonophora.' 



The other division of the Coelenterata, exemplified by Sea 

 Anemones and Corals, have few free-swimming representatives. 

 One of these, however, Arachnactis, may be expected to occur in 

 the Arctic seas. 



Echinodermata. 

 The larval forms of most of the Echinodermata (Sea Urchins 

 Star-fishes, &c.) consist of minute free-swimming organisms which 

 are among the most frequent captures of the towing net. They 

 should be removed by the dip tube from the washings of the net 

 and transferred to spirit. 



