But in thus dividing the broad zones of the Sea-Urchins, we leave the narrow zones in their original relation to them, except that every narrow zone, instead of being placed between two broad zones, has now one-half of each of the zones with which it alternated in the Sea-Urchin on either side of it and lies between them. The adjoining wood-cut represents a single ray of a Star-Fish, drawn from what we call its lower side or the oral side. Along the centre of every such ray, diverging from the central opening or the mouth, we have a furrow, corresponding exactly to the narrower zones of the Sea-Urchin. It is composed of comparatively small perforated plates through which pass the suckers or locomotive appendages. On either side of the furrows are other plates corresponding to the plates of the broad zones in the Sea-Urchin. Where shall we look for the five eyes? Of course, at the tip of every ray; exactly where they were when the rays were drawn up to form the summit of a sphere, so that the eyes, which are now at their extremities, were clustered together at their point of meeting. Where shall we look for the ovarian plates? At each angle of the five rays, because, when the broad zones of which they formed the summit were divided, they followed the split, and now occupy the place which, though it seems so different on the surface of the Star-Fish, is nevertheless, relatively to the rest of the body, the same as they occupied in the Sea-Urchin. Assuming, as we premised, that the central area of the ab-oral region, forming the space between the plates at the summit of the zones in the Sea-Urchin, is elastic, it has stretched with the spreading out of the zones, following the indentation between the rays, and now forms the whole upper surface of the body. All the internal organs of the animal lie between the oral and ab-oral regions, just as they did in the Sea-Urchin, only that in the Star- Fish these regions are coequal in extent, while in the Sea-Urchin the ab-oral region is very contracted, and the oral region with the parts belonging to it occupies the greater part of its surface. Such being the identity of parts between a Star-Fish and a Sea-Urchin, let us see now how the Star-Fish may be transformed into the Pedunculated Crinoid, the earliest representative of its Class, or into a Comatula, one of the free animals that represent the Crinoids in our day. [Illustration: Crinoid with branching crown; oral side turned upward.]