116 
POPULAR SCIENCE REVIEW. 
and described by Professor Clark, and in addition, a fourth and 
still more remarkable and luxuriant-growing variety. A brief 
announcement of this discovery within British waters of these 
interesting Flagellate types, with notes upon a few other allied 
forms, was communicated to the November meeting of the 
Royal Microscopical Society of London, and appeared in the 
Society’s Journal for January 1872. From thit period up to 
the present date continued researches by the writer in the same 
fertile field have been so far rewarded that the borders of this 
interesting, and as now shown widely distributed group, have 
had to be extended for the admission of some forty or fifty 
well-marked species. From a numerical point alone, indeed, 
it has now been demonstrated to occupy as important a position 
as any of the leading and natural divisions of the lower Protozoa 
recognized previous to this discovery; while in structural organ- 
ization they are found to exhibit so novel an aspect as to demand 
the creation of a new sectional title equivalent to that of an 
order, if not a class, for their reception. 
A glance at the two plates illustrating this article (perhaps 
already taken), will at once place the reader en rapport with the 
essential characteristics and more important known varieties of 
this newly discovered group, and which are here reproduced 
with considerable reduction in both size and number from the 
fuller details that accompany an extended monograph of the 
same now awaiting publication.* The most prominent feature 
of all these types, and one that serves to conspicuously dis- 
tinguish them from all previously known Protozoic forms, is 
the presence at the anterior extremity of each individual monad 
of a hyaline, wineglass-shaped expansion, from the centre of 
the base of which the long lash-like flagellum takes its origin. 
On this remarkable wineglass-shaped structure Professor Clark 
originally bestowed the appropriate title of the 6 collar,’ and by 
this appellation it will hereafter be distinguished. Specifically, 
this delicate hyaline organ, the collar, is of such extreme tenuity 
that its true form and nature can be brought out only by a very 
careful adjustment of the achromatic condenser or other accessory 
illuminating apparatus employed, and is even then exhibited 
to the greatest advantage by supplying the type under examina- 
tion with artificial food, such as carmine or indigo. Under the 
condition last premised it will be found that this collar consists 
of a thin infundibuliform film of sarcode that may be protruded 
from and withdrawn at will into the general substance of the 
monad’s body in the same manner as the sarcode prolongations 
* These fuller details are embodied in “A Monograph of the Collar- 
bearing Flagellata, &c., &c.” communicated to the meeting of the Linnean 
Society held June 21, 1877. 
