OF THE FLOSCULAEKEA. 



675 



each surmounted by a pencil of long setae. These lobes are regarded by 

 Ehrenberg as the rotary organ ; but, according to Gosse, the upper surface 

 of the central disc fulfils the rotatory functions. Body furnished with a 

 long peduncle, by which the animal is fixed, and the whole surrounded by 

 a thin diaphanous case resembling that seen in the very young Melicerta. 

 Erom its transparency this can often be detected only by colouring the 

 wat^r with some pigment. Alimentary canal simple, conical. Reproductive 

 system resembling that of Lacinularia. Ova deposited T\ithin the case. 

 When viewed from above, the head of the animal resembles an Acineta. 



Floscularia prohoscidea. — Case cy- 

 lindrical, hyaline, gelatinous. Setigerous 

 lobes six, with short cilia sm'rounding a 

 ciliated flexible proboscis, which appears 

 to have an opening at its extremity. 

 Dujardin thinks this proboscis may be 

 nothing more than one of the ciliated 

 lobes advanced towards the centre. Body 

 ovate, ^^'ith a long styliform peduncle 

 attached to the base of the case ; when 

 extended, the body and part of the foot 

 are protruded. Found upon the leaves 

 of Hottonia palustris. Length when ex- 

 tended 1-18"; case 1-36". 



F. ornata {Cercaria, M.) (xxxn. 384, 

 385). — Case or envelope hyaline; very 

 thin at its upper extremity ; thicker, and 

 often with foreign bodies entangled in 

 it inferiorly. It is sometimes very slug- 

 gish, but at others moves with consider- 

 able activity, often contracting itself very 

 quickly within its case. The setigerous 

 lobes, according to Gosse, are not the 

 true rotatory organs : '' yet," he says, 

 '^ there is a rotatory organ — the par- 

 ticles of floating matter revohing in a 

 pei-pendicidar oval within the mouth of 

 the disc. Hence I conclude that the 

 rotatorv cilia are set on the inner surface 

 of the disc." He fm-ther adds : "When 

 the pencil of united tufts is in process 

 of expansion the hairs have a wavy, 

 quivering sort of motion, but when ex- 

 panded they remain perfectly motionless. 

 The two red eyes seen in the young 

 animal ordinarily disappear in the adult ; 

 but Mr. Gosse has occasionally met "«dth 

 such specimens in which they were still 

 plainly visible. He has observed the 

 body " to be lined with a yellowish 

 vascular membrane, which does not ex- 

 tend up to the petals, but temiinates at 

 the neck with a free, very mobile edge, 

 forming an irregidar opening, the out- 

 line of which is constantly changing by 



the contraction and expansion of the 

 membrane. The opacity of this lining 

 renders it diflicult to resolve the viscera." 

 "Ehrenberg speaks of an oesophageal 

 head above the jaws ; but I can see 

 nothing of the kind, and am inclined to 

 think he may have mistaken the ever- 

 contractmg opening of the lining mem- 

 brane for one." These animals are very 

 fond of Chlamidomouas ; and when swal- 

 lowing large bodies, such as Naviculce, 

 they contract the entire body. Ehr- 

 enberg has numbered as many as five 

 ova retained within the diaphanous case 

 at the same time. Gosse once counted 

 nine. These, as is also the case in Meli- 

 certa, are generally in different stages 

 of development, — in some the per- 

 fectly-formed embiyo being distinctly 

 \dsible, its movements and its two reel 

 eyes being very manifest. With a mo- 

 derate pressm-e Ehrenberg burst the shell, 

 which, according to Gosse, is calcareous : 

 the young animal crawled out with a 

 slight vibratory motion ; the cilia were 

 short and not very distinct. In the 

 mature animal the pedimcle is truncate 

 at its extremity. Upon Ceratophyllum 

 and similar plants. 1-108". In xl. 25 

 the dorsal aspect of the jaws is repre- 

 sented, and in 26 their frontal aspect. 



Dr. Dobie writes {A.N.H. Oct. 1849) : 

 " Ehrenberg regards the Floscidaria de- 

 scribed and figured by M. Peltier, as 

 identical with his F. ornata. Both Du- 

 jardui and Peltier found the rotaiy organ 

 tive-lobed in the species observed in 

 France ; so we must either hold with 

 Pritchard that F. ornata has sometimes 

 five, at others six lobes, or consider the 

 five-lobed species a variety of F. ornata. 

 .... My friend Mr. Hallet writes me that 

 he finds F. ornata -^-ith a six-lobed ro- 

 tary organ and no process." 



The two next species and accompanying remarks are taken from a paper 

 by Dr. W. M. Dobie {A. N. H. Oct. 1849). 



F, campanulata. — Case diaphanous, | fringed with very long cilia ; body ovate, 

 rotary organ with five flattened lobes, | Tsnthout proboscis ; tail long, and termi- 



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