HARDWICKE'S SCIENCE-GOSSIP. 



*33 



Lucernariadae are shapeless, like a mass of thick brown 

 jelly, which sticks firmly to the hand. Campanulata is 

 found at Ventnor. The Lucernaria is very lively, 

 swaying its tentacles to and fro in search of food. 

 They swim with some rapidity by alternately expand- 

 ing and contracting the body, the adhering power is 

 doubtless of service to the animal in capturing food, 

 as well as for fastening itself to Algoe. 



Another species, L. cyathiformis, has been described, 

 having the tentacles in a fringe all round the cup ; I 

 have not met with this form. I think it likely several 

 new species may be detected in this family. 



Fig. 81. — Lucernaria 

 auricula (natural 

 size). 



Fig. 82. — Lucernaria auricula 

 (magnified), showing ova. 



Fig. 83. — Iluanthus (natural size, Isle of Wight specimen). 



Iluanthus. — Although'not in the same family with 

 Lucernaria, the Iluanthus is somewhat similar, and is 

 found in the same situation as the former. It belongs 

 to the Actiniadse, but is different from any other genus. 

 E. Forbes has described it thus : body cylindrical, 

 tapering to a point at its posterior extremity, free. 

 Tentacula simple, retractile, surrounding the mouth. 



Only one species has been named, but I think in 

 the Isle of Wight we have two : I. scoticus, a most 

 restless creature, extremely irritant. Body circular 

 and worm-like ; tentacles very long and too numerous 

 to count. Under the inch power a most beautiful 

 object. It is named from its partiality to muddy 

 situations — occasionally it lies on the mud, shapeless 

 as if dead ; on being touched it wriggles away angrily 

 and is difficult to catch. I believe they are of rare 

 occurrence. Body about an inch long, pure white or 

 sometimes having the body streaked with red. In 



three specimens I have caught the body is longer and 

 very much slighter than the one figured by Johnston ; 

 the others answer exactly to his descriptions. It is 

 possible they represent different stages of growth. 

 Johnston only names two localities for this curious 

 free-swimming Actinia ; one in Scotland, the other 



Fig. 84. — Iluanthus scoticus (after Johnson). 



in Ireland. I should like to know if any of your 

 correspondents are acquainted with Iluanthus in 

 other parts of England besides the Isle of Wight? 

 Fig. 83 shows the difference between two speci- 

 mens ; the body and a tentacle slightly enlarged 

 on the left hand. C. Parkinson. 



THE EARLY HISTORY OF THE 

 DIATOMACE/E. 



By F. Kitton, Hon. F.R.M.S. 

 [Continued from / age 79.] 



BORY opposed Gaillon in the article Nemazoaires 

 ("Diet. Class. d'Hist. nat."). But Meyen 

 again contended with Leo and Girod Chantrans that 

 Bacillaria were produced by Oscillatoria. Agardh 

 agrees (1828) with Leiblein in placing Closterium 

 in the family Diatomeae, in which he was also 

 disposed to place Spongilla lacustris. In the year 

 1858 Meyen constructed the genera Pediastrum 

 (Micrasterias) and Scenosdesmus (Arthrodesmus), 

 Staurastrum and Sphserastrum (these are now placed 

 in the family Desmidese, — F.K.) and which he looked 

 upon as sports of the plastic power of nature (" Spiele 

 der bildenden Natur ") and described them as plants. 

 Reichenbach placed the Bacillaria in the family 

 Confervacea. Turpin, in the same year, constructed 

 his genus Surirella * (Navicula), and which he 

 considered as hovering between plants and animals. 

 Agardh (1830), in his first academical thesis on the 

 Diatomese, changes the name Frustulia to Cymbella ; 

 and, in the same year, Blainville asserts the Bacillaria 

 to be plants. I, at this time, removed the Bacillaria 



* Ehrenberg adopts this genus in his " Mikrogeologie." 



