INTRODUCTION TO ZOOLOGY. 



living squadrons of this little mariner (Fig. 1 8), have been 

 observed while passing the picturesque headlands of the 

 Giant's Causeway, or the basaltic bulwarks of the harbour of 

 Ballycastle, on the coast of the County Antrim. 



FIG. 18. VELELLA. 



Upon the southern shores it is, however, of more frequent 

 occurrence. There the specimen was taken of which, by the 

 kindness of Professor Allman, we are enabled to give a figure 

 of the natural size. The original drawing by that gentleman 

 was from a living Velella, respecting which he remarks: 

 "The individual who sat, or rather floated, for. his likeness, 

 was one of a fleet of countless multitudes, which, in the 

 Autumn of 1836, was driven upon the coast of. the County 

 of Cork. On the subsidence of the gale, which had been 

 blowing strongly from the south-west, the coast for miles 

 round was strewn with the remains of the shipwrecked fleet." 



r fhe occurrence of species such as those mentioned. is rare; 

 and it is, therefore, desirable to convey some knowledge of 

 the structure and habits of the Acalephae, not by those which 

 may seldom or perhaps never be observed by the generality 

 of men, but by those which are abundant on our shores, and 

 may be seen and studied by all. 



If, during the fine weather of summer or autumn, a gauze 

 towing-net be attached to a boat which is rowed gently along, 

 it is probable that, if the net be examined after a short time, 

 there will be found among its contents some transparent 

 bodies, differing in size, but in general about as large as a 

 boy's marble. Externally they exhibit ridges like those of a 



