THE CROWN ANIMALCULE. 
49 
and habits will, I have no doubt, abundantly repay investigation 
by careful observers with good instruments, as there are many 
points in its economy on which we need further light. 
EXPLANATION OF THE ILLUSTRATIONS. 
Plate III. represents an adult female Stephanoceros Eichhornii, magnified 
one hundred diameters. A young one, just hatched, is seen within the 
parental case, working its way upward to liberty. 
Plate IY. — Metamorphosis and development of the same. Fig. a, The egg 
just ready for hatching : b, The young, fifteen minutes after birth, permanently 
attached, with the first elements of the case deposited : c, The same, twenty- 
five minutes old, with a new segment to the case : cl, Another individual, four 
hours old : e, One, three hours old. The development in these two is at about 
the same point, but that of the case in e, though the younger, is rather the 
more advanced : /, cj, h, Intermediate conditions, from six to twelve hours 
old : i, The adult form perfectly developed, at thirty-six hours after birth. 
Figs, b, c, e, g, and i, represent the same individual. In each figure, the foot 
of the animal must be understood to be adherent to the farther surface of a 
plate of glass, and the case to be attached around it, so that both animal and 
case project from the eye. 
For fuller information on all that has been published concerning this species, 
the reader is referred to Ehrenberg’s Memoir, in the “ Berlin Transactions” 
for 1831, and his “ Infusions-thierchen to Dr. Mantell’s “ Thoughts on Ani- 
malcules,” and to Dr. Franz Leydig’s admirable Memoir on the Rotifera, in 
Siebold and Kolliker’s “ Zeitschrift,” for July, 1854. The new edition of 
Pritchard’s “ Infusoria” (1861) contains a valuable summary of the researches 
of the continental savans on the whole class, including, of course, the present 
species. 
NO. I. 
E 
