Picture - Cosmic Polymath

174 DESIGN IN NATURE
PLATE LXXII
PLATE LXXII {continued)
band whicla confers spiral movements on it. Illustrates the spiral action of the pedicle and the power of expanding and contracting
the body by centrifugal and centripetal movements.
Fig. 21. —Adherent zooid {Scyphidia rugosa) in the expanded and contracted states, x 280 (Dujardin). Body pyriform, attached
posterior extremity most attenuate; integument furrowed obliquely and spirally in two directions; pharyngeal cleft prolonged.
Shows how spiral markings and structures are affected by centrifugal and centripetal movements (the Author).
FicJ. 22.—Lorica or protecting sheath with two zooids (Cothurnia patula) in the contracted condition, x 200 (De Fromentel).
Fig. 23.—Shows the same lorica and the same zooids (Fig. 22) in the extended condition. These figures illustrate in a striking
manner the centripetal and centrifugal movements of zooids (the Author).
Figs. 24 and 25.—Two zooids {Cothurnia cohnii and Cothurnia pwpa), x 400 (Cobn and Eichwald), occupying elegantly shaped
lorica with annular transverse markings. At Fig. 24 the lorica is elongate ovate and subcylindrical ; the anterior margin being
abruptly truncated. At Fig. 25 the lorica is symmetrically ovate and widest in the middle.
Fig. 26.—Colony stock of Opercularia stenostoma, x 200 (D'Udekem). Bodies elongate and pyriform, widest in middle and
tapering finely towards pedicle, which is small, rigid, and dichotomously divided. Peristome border and ciliary disc very narrow ; the
latter bearing an elegant single circlet of cilia. The general appearance is plant-like. The zooids are provided with remarkable
ciliated lids resembling those of the trap-door spiders.
Fig. 27.—Adult colony stock of zooids {Zoothamnium carcini) in an inverted position, x 80. Illustrates branching distribution
of zooids.
Fig. 28.—Terminal branchlet of colony stock of zooids {Carchesium epistylidis) as figured by H. E. Forrest, x 300. The zooids at
the left of the figure are expanded or open ; those at the right contracted or closed. Furnishes example of centrifugal and centripetal
movements.
Fig. 29.—Termination of branchlet showing unilateral distribution of zooids {Carchesium polypinum), x 150. Figs. 28 and 29
jiresent a general flower-like appearance.