38 THE VICTORIAN NATURALIST. 



A NEW ROTIFER— MJELICHUTA FIMBRIATA. 



By J. Shephard and W. Stickland. 



{Read before the Field Naturalists' Club of Victoria, \Qth Jan., 1899.) 



In a gathering from the Botanical Gardens, Melbourne, we met 

 with a rotifer, a Melicerta, presenting characteristics sufficiently 

 differing from previously described species to lead us to regard it 

 as new. 



The genus Melicerta has hitherto comprised four species. 

 Of these M. ringens and M. conifera are remarkable for their 

 habit of constructing an outer casing to the tube in which they 

 live, consisting of pellets made by means of a special organ. 

 Both the other species possess the pellet-forming organ, but are 

 said not to use it — M. janus fortifying its tube with pellets 

 of faecal matter, while M. tubicolaria possesses only the 

 gelatinous tube, figured by Hudson and Gosse as very similar to 

 those of the genus Floscularia, 



The pellet-forming species are well known here ; but the other 

 two are, we believe, unrecorded. The animal forming the 

 subject of this paper was found on stems of Nitella, in company 

 with Al. ringens, several species of Limnias, and Stephanoceros 

 eichornii ; this latter beautiful object being observed for the first 

 time in Victoria. The general appearance at once suggests 

 Melicerta tubicolaria, but the tube is built up of light brown 

 fibres, each possessing a granular structure arranged so as to 

 radiate somewhat irregularly from a thin gelatinous tube which 

 fits closely to the body. The whole appears flexible, and is 

 readily broken up. Older specimens were noticed whose tubes 

 had almost entirely lost the brown colour, but their fibrous 

 nature could still be detected, though with difficulty. In one 

 case the middle portion of the tube was quite pale, while the 

 two ends were coloured. The thickness of the tube wall varies 

 from twice to four times the width of the animal's body, and the 

 filaments composing it are long in proportion to their breadth. 

 The body of the rotifer is usually extended well out of the tube, 

 and when fully stretched is long and tapering. The corona 

 much resembles that of M. tubicolaria in outline and width 

 when seen in the dorsal aspect ; but the dorsal gap appears wider 

 than in that rotifer, though not nearly so wide as in M. ringens. 

 The two ventral antennae are shorter than those figured for 

 M. tubicolaria, not extending to the upper portion of the corona, 

 and possess much flexibility, being sometimes bent into the form 

 of a hook, but usually project more laterally than forward. 

 Considerable search revealed a dorsal antenna placed high up in 

 the neck, near to the trochal disc, and of somewhat unusual 

 form, having a flat expansion bearuig set^, and supported by a 

 very short peduncle ; this is best seen when the animal is in the 



