GO THE EOTIFEEA. 



Genus STEPHANOCEROS, Ehrenberg. 



GEN. CH. Lobes long, slender, erect, convergent ; setse set diagonally on the lobes 

 arallel bands ; foot terminated by an adhesive cup. 



S. eichhoenii, Ehrenberg. 



(PI. IV. fig. 1.) 



Stephanoceros Eichhornii . . Ehrenberg, Die Infus. 1838, p. 400, Taf. xlv. fig. 2. 



„ . . . Dujardin, Hist. Nat. Zooph. 1841, p. 612, pi. xix. fig. 8. 



,, ,, Gosse, Popular Sci. Bev. vol. i. 1862, p. 30, pi. iii. and iv. 



Stephanoceros glacialis . . . Perty, Zur Kenntniss kleinst. Leben&f. 1852, p. 47, Tab. i. 



fig, 1. 

 Stephanoceros Eichhornii . . Leydig, Ueb. d. Baud. Bdderth. 1854, p. 5, Taf. i. figs. 1-4. 

 ,, „ . . . Pritohard, Infusoria, 1861, p. 0U8, pi. xxxii. rig. 383, 



pi. xxxvii. figs. 1-4. 

 „ . . . Cubitt, Mon. Micr. J. vol. iii. 1870, p. 240, pi. Iii. 



,, ,, . . . Newlin Peirce, Proc.Acad. Nat. Sci. Pa. 1875, p. 121. 



„ ,, Eosseter, J. Boy. Micr. Soc. 2 Ser. vol. iv. 1881, p. 169, 



pi. v. figs. 1-3. 



Anyone who lias seen Stephanoceros favourably placed, and properly lighted, can 

 well understand the enthusiasm with which Eichhorn relates its discovery ' ; for it is a 

 lowly creature, and as strange as it is beautiful. A small pear-shaped body, whose 

 rich green and brown hues glow beneath a glistening surface, is lightly perched on a 

 tapering stalk, and crowned with a diadem of the daintiest plumes : while the whole is 

 set in a clouded crystal vase of quaint shape and delicate texture. The tube is denser 

 than it is in the Floscules, is more symmetrical in shape, and is continuous in sub- 

 stance from its outer surface almost to the creature's body. If an empty tube be 

 examined, it will be found that it has a central hollow, which the body and foot will 

 exactly fill. 



Mr. Gosse and Dr. Mantell have each seen a young Stcplianoceros bore its way 

 through its parent's tube by means of its cilia ; just as I have several times seen young 

 Floscules do. The material, therefore, of which it is composed, must be of the flimsiest 

 kind. The commencement of the formation of the tube has been described by Mr. Gosse 

 [loc. cit.) as follows : " A specimen, which was hatched under my eye, swam for ten 

 minutes, and then became permanently attached to the upper glass of the box, so that it 

 was vertical in its position, with the foot next to the eye ; a favourable aspect for 

 observing the development of the case. It presently began to dilate its body ; and, in 

 about five minutes from its attachment, I perceived a distinct filmy ring around it, per- 

 fectly circular, whose diameter was about twice that of the body |P1. IV. fig. 8). The 

 little animal now began to lean over to one side, and the ring soon had another segment 

 additional, leaning in the same direction (fig. 9). The case, for such it was, looked like 

 two broad hoops of glass, each swollen in the middle and set one on the other but not 

 quite concentrically, at least to the eye of the observer. It was manifest that it was 

 produced from an excretion from the body, owing its form and size to the animal's mov- 

 ing round on the foot as on a pivot." 



Ehrenberg's drawing of Stephanoceros has certainly been taken from a crushed or 

 sickly specimen, and, indeed, in the majority of cases its portrait has been drawn too 

 long after the creature had left its native haunts ; for when freshly caught and in 

 vigorous health it arches its five plumes so that its crown almost forms a sphere. 2 The 



1 P. 18, supra. 



- Mr. Gosse has found that healthy specimens, removed from an aquarium and inspected at once, 

 have their live arms more frequently produced into a cylindrical form, with their extremities incurved, 

 than arched into a sphere. 



