170 



THE VOYAGE OF H.M.S. CHALLENGER. 



behind the ganglia and just above the mouth, which, semicircular as usual, leads into a 

 folded intestine terminated by an anus. Length 0*75 mm., breadth 0*25 mm." 



On the 25th a very large colony of a new species of Pyrosoma was captured in the 

 trawl ; the cylinder was 4 feet 2 inches in length, and 10 inches in diameter, closed at 

 one end, and, as in the smaller forms, the colony was spotted with red, the red spots being 

 the visceral nuclei of the several animals. The specimen was kept in a tub of water till 

 after dark, when it gave off brilliant phosphorescent light on being disturbed. The 



Fig. 69. — Ophwylyplta bullala, Wyv. Thorns. Dorsal aspect; three times the natural size. 



officers amused themselves by writing their names along this living cylinder with one 

 finger, the track of which remained as a bright line of light for some seconds. Salpce 

 were the commonest animals in the surface waters ; there were several kinds, and many 

 long bands of them in the chain form were taken in the surface nets. Brilliant 

 phosphorescence was observed at night during calm weather, and the following are some 

 of the animals taken near the surface on these occasions : — Foraminifera, Radiolarians. 

 Gleba, Diphyes and other Siphonophora, Medusae, Sayitta, Alciope, Cypris-larvse of 



