In Chimaera all three basalia are present, but the meso-pterygium is shifted and does not articulate with the pectoral girdle[49].
In Rays the propterygium and the meta-pterygium are long and narrow and diverge much from one another; other basalia work their way in between the meso-pterygium and meta-pterygium, and come to articulate with the pectoral girdle.
In the adult male dogfish the distal end of the basi-pterygium bears a stout rod nearly as long as itself, and grooved on the dorsal surface.
The meta-pterygium bears about twelve long narrow radials, the first nine of which are traversed by a transverse joint at about two-thirds of the way from their origin.
In Amia, Lepidosteus, and certain Teleosteans like Salmo, not only the propterygium but the meso-pterygium is almost suppressed by the marginal ray.
In Polypterus the pro-and meta-pterygia have ossified while the meso-pterygium remains chiefly cartilaginous; the fin-rays are also chiefly ossified.
The meso-pterygium also supports only a single radial which divides distally.
The males in Elasmobranchii and Holocephali have the distal end of the meta-pterygium prolonged into a clasper.
By some authors the meta-pterygium and by others the meso-pterygium is regarded as homologous with the axis of the archipterygium.
There is always a large basi-pterygium which lies imbedded in the muscles and meets its fellow at its proximal end.
In some of the sharks, including the Notidanidae and Scyllium, all three basalia articulate with the pectoral girdle, while in others such as Cestracion the meta-pterygium is excluded.
When the pterygiumis of considerable size, extending over the cornea, the only remedy is excision.
The base of thepterygium is always on the circumference of the eye, generally at the inner corner, and its apex is seldom, if ever, situated beyond the centre of the cornea: frequently the sclerotic conjunctiva alone is affected.
Under adrenalin and cocaine the neck of the pterygium is seized with the forceps and the body and neck are carefully dissected from the conjunctiva.
Pterygium should be removed when advancing across the cornea, especially when the pupillary area is becoming involved.
If there be a fleshy excrescence it may be excised with a pterygium knife or the polypus scalpel' (VI.
In the first the pterygium was raised by a small sharp hook, and a needle carrying a horsehair and a strong flaxen thread was passed under it.
Horsehair was used to raise a pterygium in Paul VI.
The base of the pterygiumwas then severed with the scalpel for the plastic operation on entropion.
Albucasis, who conveys entire the passage on pterygium from Paul, gives figures of both these instruments.
Tension being made on the thread by an assistant, the operator sawed off the pterygium towards the apex by means of the horsehair.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pterygium" in a variety of sentences. We hope that you will now be able to make sentences using this word.
