On. VI.] PTEEOPODS AND AOALEPHS. 99 



time. At one time the towing-net would bring up trans- 

 parent animals which bore a close resemblance to the 

 Cymbulia ovularis, of Eang, whose broad expansive wings, by 

 which locomotion was effected, were placed in a tuberculated 

 and purse-shaped crystal calyx, from which it was easily 

 separable, the whole animal being ia some lights invisible 

 but for an oblong black spot in the centre. Another of 

 these transparent Pteropods was the Pneumodermia ; but 

 the most abundant and striking was the pretty and delicate 

 little Creseis, with an elegant glassy shell, like an inverted 

 church spire, pointed like a needle at one end, while, from 

 the other, a pair of little delicate wings would keep the calm 

 surface of the water in a constant ripple by their soft flapping 

 to and fro. So abundantly did these little creatures swarm 

 upon some days, that they came up in solid masses, and the 

 towing-net was filled with them in every mesh ; so that it 

 was a long task to clear it of the fragile shells. 



Beautiful Acalephs, or sea-jellies, too, were among the 

 harbour's inhabitants ; cUiogrades, like elegant pink glass 

 flowers, in constant motion, with prismatic bands of cilia 

 playing along the raised ridges of their body from end to 

 end. But even these were hardly so striking as the wonder- 

 ful influx of Hydrozoa, of the singular genus Stephanomia, 

 that occurred one evening. This happened upon the 18th of 

 June. Although calm, it had been a wet day ; yet, in spite 

 of this, myriads and myriads of Creseis swarmed in the^ 

 harbour. During the day a breeze sprang up, and at times 

 rollers came in ; but as the afternoon advanced, the sea 

 became alive with marine animals, including some of the 

 forms I have already described, but chiefly beautiful organisms 

 which most closely resembled the Stephanomia triangularis 

 of Quoy and Gaimard. They were wonderfully sculptured 



