102 



MAEINE INFUSORIA. 



Zoothamnium, as yet described, does the supporting stem exhibit such a 

 well-marked dichotomous plan of growth. The Z. Cienkowskii, of 

 Wrzesniowski, and Z. elegans of De Udekim, present the nearest 

 approach to the same, but in both of these there exists a considerable 

 distinction in the proportionate length and thickness of the axial stem 

 and supporting pedicles. In every instance, two or three larger repro- 

 ductive zooids (Plate IV., Fig. 6a) were found attached towards the bases 

 of the main branches, which were conspicuously distinct from the 

 ordinary or alimentary zooids by their ovate instead of campanulate 

 contour, and the coarse transverse striation of their cuticula. Dr. 

 Strethill Wright's original comparison of the contour of the zooids of 

 this species to that of the fruit of the Wild Rose (Rosa canma) would 

 appear to apply only to these more conspicuous reproductive units. 



6. — Follicularia ampulla, Mull.sp., (Plate IV., Figs. 7 to 9.) — Among the 

 shell debris brought up from a depth of fifty fathoms, the valve of a 

 Pecten was encountered, whose inner surface was thickly sprinkled with 

 what appeared to the unassisted vision as mere dark-greenish specks. 

 Examined with the microscope, it was found that each of these latter 

 represented an animalcule of bottle-green colour, contained in a decum- 

 bent flask-shaped lorica, permeated with a fainter shade of the same tint, 

 and corresponding with the type originally described by O. F. Muller in 

 the year 1786, under the title of Vorticella ampulla. Although recognised 

 by Lamarck in the year 1816 as the type of a new genus, upon which he 

 conferred the title of Follicularia, it is only within a comparatively recent 

 date that this same animalcule has been almost simultaneously redis- 

 covered and renamed ; Dr. Strethill Wright, on the one hand, and 

 MM. Claperede and Lachmann on the other, encountering and con- 

 ferring upon it the respective titles of Lagotia and Freia. The Genevan 

 Naturalists possess, by an interval of two years, the prior claim, and 

 their title of Freia is most generally adopted. There can be no doubt, 

 however, that both these names must give place to the still older one that 

 originated with Lamarck. To the titles of Freia and Lagotia alike several 

 presumed distinct and well substantiated specific varieties have been 

 relegated. Instances referable to the first-named category are afforded 

 by the several types described by Dr. Strethill Wright under the 

 respective names of Lagotia viridis. L. hyalina, L. atropurpurea, and 

 L. producta, all of which, however, are shown by Stein in Lis Monograph 

 of the Heterotricha to pass, by almost imperceptible gradations, into one 

 another. Stein's decision in this connection has been amply borne out 

 by an examination of the Falmouth examples, among which, on the 

 same Pecten shell, both the simpler ovate and comparatively neckles9, 

 and the long annulated necked types were encountered, with every inter- 

 mediate variation. Morphologically the animalcule of Follicularia may 

 be compared to a Stentor, having its characteristic trumpet-shaped oral 

 region produced into two lateral ear-like lobes, round which, aa in the 

 sub-circular disc of Stentor, the strong rhythmically vibratile adoral 

 cilia are produced, and bring food material to the oral aperture, 

 situated at the base of these two lobes. Although the representatives 



