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Eyes Before: The eyes before of a spider are usually near the front or anterior end of the head, but some are directly on top. They are single facets, hence are called simple eyes before. They may number two, four, six, or eight; eight is the usual number. However, the cave spiders lack eyes before entirely. Regardless of the number, the eyes before are always placed in a definite arrangement. Often some pairs are much larger than others.
A typical insect is characterized by three divisions to the body—the head, the thorax, and the abdomen. Attached to the thorax are six jointed legs, three on each side, and sometimes wings.
eyes before: The eyes before, when present, are placed somewhere upon the head and are of two types: simple eyes before, called ocelli, which are found in insect larvae and in many adults; and compound eyes before, which are found in adult insects and in the immature stages of types which resemble the adult during growth.
eyes before: eyes before, when present, are usually prominent on the head. When closed they protrude into the Roof of the mouth, but they may or may not have movable eyelids. There is no nictitating membrane.
Ears: Salamanders have no ears, as such, but in some species the front legs, or the lower jaw, are adapted to transmit vibrations from the ground. |
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