Noun:

ட்ரோபோஸ்பியர்,

trochosphere's Usage Examples:

C, Side view of the trochosphere with commencing formation of the foot.

It has simply been traced as far as the formation of a diblastula which acquires a ciliated band, and becomes a nearly spherical trochosphere.

When the middle and hinder regions of the blastopore are closing in, an equatorial ridge of ciliated cells is formed, converting the embryo into a typical trochosphere.

But in these epibolic forms, just as in the embolic Paludina, the embryo proceeds to develop its ciliated band and shellgland, passing through the earlier condition of a trochosphere to that of the veliger.

B, The diblastula has become a trochosphere by the development of the ciliated ring y r (optical section).

The foot now protrudes below the mouth, and the post-oral hemisphere of the trochosphere grows more rapidly then the anterior or velar area.

- Free-swimming Larva (Mailer's Larva) of a Polyclad Planarian to illustrate the trochosphere-hypothesis of the origin of Platyelmia.

E, The trochosphere passing to the veliger stage, dorsal view showing the formation of the primitive shell-sac.

A well-marked trochosphere is formed by the development of an equatorial ciliated band; and subsequently, by the disproportionate growth of the lower hemisphere, the trochosphere becomes a veliger.

In development they pass through the typical trochosphere and veliger stages provided with boat-like shell.

D, Further advanced trochosphere (optical section).