The spines in both rows increase in size away from the umbo and there are a few rare scattered additional spines on the ventral corpus. |
|
Argonauta attaches the egg-mass to the umbo of the shell near the dorsal arms, not in the mantle cavity or posterior parts of the shell. |
|
The oldest part of the shell, the umbo, can be recognized as a large hump on the anterior end of the dorsal side of each shell. |
|
Later, when the larva reaches 115 µm, the umbo moves to the side, becoming offcentred and protuberant. |
|
The umbo forms at the point where the two valves meet and becomes protuberant early in the larva's development. |
|
The larva remains symmetrically shaped until about 240 µm, at which size the umbo extends above the hinge line and becomes more protuberant. |
|
The motion of the membrane is transferred to the handle of the malleus, the tip of which is attached at the umbo. |
|
When the larvae reach this size, the umbo looks like a round protuberance hiding the straight hinge line. |
|
Larvae larger than 210 µm have a more protuberant umbo, and their sides form obtuse angles with the shoulders. |
|
When the tympanic membrane absorbs sound waves, its central portion, the umbo, vibrates as a stiff cone, bending inward and outward. |
|
The shape of the umbo can also depend on the position of the larva when it is being observed. |
|
From about 140 µm, the umbo is projected above the hinge and becomes angular. |
|
The umbo then develops quickly and always remains in the centre of the dorsal part. |
|
In mussels, the umbo is indistinct, while the rock borer's is angular in shape. |
|
In the earliest stages, the umbo is below the hinge, and the larva is pale yellow in colour. |
|
The umbo of the oyster larvae moves off-centre during growth, whereas the umbo of the shipworm larva always remains centred. |
|
The oldest part of a clam's shell is near the hinge, which is called the umbo. |
|
At the centre was the umbo, a sort of iron boss to protect the hand. |
|
The mussel's umbo is more protuberant, and the outline is thicker. |
|
Intraoperatively, the tick was alive, its abdomen was distended, and its mouthpart was embedded in the tympanic membrane near the umbo. |
|
|
The outer face is slightly concave, and a tuberculate ornamentation is sometimes present in the area of the postcentral umbo. |
|
The otoscopic view is of a right ear with a green Silastic grommet in proper position inferior to the umbo. |
|
The mussel's umbo is not apparent or does not extend above the hinge. |
|
The umbo, low and rounded, appears below the hinge. |
|
When the larva reaches 200 µm, it becomes pointed with an angular umbo. |
|
They then develop into a fully shelled veliger larvae, also known as the late umbo stage, which have a hinged side and a velum, formed within 12 to 24 hours. |
|