598 ORDER HETEROTRICHA. 



upwards ; neck short in young individuals, but becoming much prolonged 

 with age and usually ornamented with either horizontal or spirally ascending 

 annulations or with longitudinal flutings ; margin of aperture even, circular ; 

 animalcules similar in colour to the sheath ; peristomal lobes subequal, 

 attenuate, from three to six times as long as broad, their extremities more 

 usually bluntly, but sometimes sharply pointed. Length of body of lorica 

 1-380" to 1-60", neck varying from one-quarter to the entire length of the 

 body portion. Hab. — Salt water. 



This species, representing the Vorticella ampulla of O. F. Muller, the Folliatlina 

 ampulla of Lamarck, and the Freia ampulla of later writers, varies so greatly in the 

 form and aspect both of the lorica and contained animalcule, in accordance with its 

 age or local deri\ ation, that it has received a variety of names from the several 

 authorities who have encountered and described it. Stein, however, who has made 

 this genus the subject of special study, unhesitatingly refers to different stages or 

 varieties of a single species all those t}'pes described under the respective titles of 

 Freia ampulla and F. aaileata by Ciaparede and Lachmann, the Lagotia viridis, 

 L. hyalina, and L. airo purpurea of Strethill Wright, and the Freia americana of 

 Dr. Leidy. Wliile concurring with Stein generally as to the necessit)' of abolish- 

 ing, as mere synon}Tns of the present type, the several nominal species above 

 enumerated, the author is disposed to regard as a possible distinct form Claparede's 

 variety illustrated by PL XXIX. Figs. 21 and 22, distinguished by the exceedingly 

 acuminate contour of the peristomal lobes ; this at any rate may be retained 

 as a well-marked subspecies under the title of FolUculiua ampulla van acukata. 

 The Lagotia viridis of Strethill \\'right accords with the normal adult condition 

 of the present species, while his L. hyalina, distinguished merely by the transparence 

 or absence of colour in the lorica and contained animalcule, is evidently the young 

 condition only of the same form. The Lagotia {Folliailaria) atro-purpurea is admitted 

 by the last-named authorit)- to be probably a mere variety only of his L. viridis, 

 it being found in company with that t^-pe, and differing from it only in the more 

 inky hue of the parenchyma and the yellowish-brown colour of the lorica. 



Stein reports the occurrence of Folliailina ampulla in countless numbers upon 

 the spiral shells of the tubicolous annelid Spirorhis nautiloidcs, these themselves 

 being attached to the fronds of the bladder-wrack, Fuais vesiculosits. In those 

 older examples in which the neck-like portion of the lorica is greatly prolonged and 

 annulate, some approach would seem to be made towards the still more elongate 

 lorica of F. producta. The enclosed animalcule of this last-named type would, 

 however, appear to differ essentially in the narrow, Ugulate shape of the peristomal 

 lobes. As already recorded in the 'Midland Natiuralist ' for May 1880, examples 

 of both the short smooth-necked and attenuate annulated form of this species were 

 obtained by the author growing upon the single shell of a Fecten dredged from a 

 depth of 50 fathoms, off Falmouth, in July 1879. By an oversight, the Lagotia 

 [Folliculina) produeta of Strethill \\'right, presently described, has been there included 

 among the sj-nonyms of the present t3'pe. 



Folliculina elegans, C. & L. sp. Pl. XXIX. Figs. 33-35. 



Lorica flask- or bottle-shaped, transparent or pale green, attached 

 laterally ; the neck bent upwards, very much shorter than the body of the 

 sheath, everted at its margin, frequently with a lateral lunate excision, 

 containing interiorly several angular valve-like appendages which close 

 the aperture when the animalcule is contracted ; body of animalcule trans- 

 parent or pale sea-green, lobes of the peristome of equal size, ovate, about 



