THE MICROSCOPE. 185 



Campanularia volubilis (on Cemmium ciliatum, Plate XIX). — 

 This beautiful zoophyte must have been lovely indeed in life, 

 relieved by the delicate pink of the graceful Alga it made its 

 home upon. A summary account of Campanularia will be found 

 in the Micrographic Dictionary ; Johnson's ^•British Zoophytes'" 

 may also be consulted, and a recent work on the same subject by 

 the Rev. Thomas Hinck, B.A., F.L.S. The creeping main-stem 

 whence the polypes arise must be carefully looked for ; it is not 

 readily seen, so closely does it adhere to that of the Alga. The 

 animal has but one orifice, which serves alike for the reception of 

 food and the voidance of effete portions. In life, a circulation of 

 granular particles may be distinctly seen up and down the slender 

 stems, and at times, though with more difficulty, along the main 

 stem. The arms vary in number in different genera and species ; 

 here there are from fourteen to sixteen. Their motion is very 

 slow, their action not consentaneous, as in the Bryozoa. They 

 are rough and modulated along their edges ; this arises from the 

 presence of stinging organs, which consist of delicate filaments 

 seated in capsules and ejected when required. In some of the 

 larger Actiniae — e.g., A. crassicornis, the urticating effect of these 

 organs may be sensibly felt when they are handled, and, under 

 high powers of the microscope, seen when a small portion of the 

 arm is examined. None shows them better than the common 

 A. mesembryanthemum. At certain periods of the year ovicells 

 are to be found ; these are ovate vesicles concentrically ringed. 

 They are not in the specimen before us, but I have added a figure 

 (a) to assist in directing attention thereto. 



Campanularia should be mounted in shallow cells ; the cups 

 are so very tender as to be crushed by even a slight amount of 

 pressure. T. West. 



EXPLANATION OF PLATES XVIII., XIX., XX. 



Plate XVIII. 



Fig. 1.— Teeth of Testacdim, x 25. 



,, 2. — Tooth from right side on its side, x 100. 



,, 3. — Tooth from right side, ventral aspect, x 100. 



,, 4. — Coultei' of a plough for comparison, as suggested hy a member. 



Plate XIX. 



Campanularia volubilis. — Two of the polypes are drawn from the 

 specimen, ahmg with a portion of the "weed," to which they are 

 attached. The animal is from a figure taken from life at Looe in 

 Cornwall, in 1857. The figure to the left (a) is of an ovicell. 



Plate XX. 



Fig. 1.— Parts of the head of Dolichopus simplex, illustrating the 

 remarks on the antenn;e, the ocelli, and eyes, and thin 

 "lashes" or " guard "-hairs (see p. 180). 



