In these we see the familiar Carboniferous spores with triradiate markings called Triletes by Reinsch, and which are similar to those of Lycopodiaceous plants.
Some Teleosteans, like Diodon hystrix, have scales with triradiate roots from which arise long sharp spines directed backwards.
This forms a minute rod of bone, one end of which is expanded and fits into the fenestra ovalis, while the other end, terminated by a triradiate piece of cartilage, is attached to the tympanic membrane.
The shoulder girdle of the Chelonia is formed (Rathke) of a triradiate cartilage on each side, with one dorsal and two ventral limbs.
An independent mass of cartilage gives rise to a praecoracoid, which unites with the main mass, forming a triradiate bar like that of Acipenser or the Siluroids.
It always lies in the equatorial plane of the discoidal body, and always unpaired in one of its axes; in the triradiate #Discoidea# it is in the axis of the unpaired principal arm and opposite to it (Pl.
Several forms of Plagonida may also be readily confounded with the isolated triradiate or quadriradiate spicula of many Beloid skeletons (Sphaerozoum, Lampoxanthium, &c.
Often few quadriradiate or few thorny triradiatespicules are interspersed among the others.
Intermingled with these are often some few, thorny, triradiate spicula.
It bears therefore to its probable ancestral form, Stauralastrum, the same relation that in the triradiate Euchitonida Chitonastrum does to Dictyastrum.
Sporangium, showing the triradiate marking on the under surface, and a granulation produced probably by the spores in the interior.
On their under surface Mr. Carruthers has observed a triradiate ridge (Plate III.
It is therefore very probable that a great part of these Cyrtoidea eradiata (if not all) may be derived from triradiate or multiradiate ancestral forms, by reduction and loss of the radial apophyses.
In general, the triradiate Stichocyrtida are much rarer and much poorer in specific forms than the triradiate Tricyrtida, their ancestors.
The shell is more or less ovate or spindle-shaped, tapering towards {1394}both poles, and resembles greatly the triradiate Rhopalocanium.
Columella with three or four triradiate verticils, as long as the slender pyramidal horn.
Columella straight, with two or three triradiate verticils of horizontal lateral branches, which are inserted in the shell-wall.
Columella with five or sixtriradiate verticils of lateral branches.
Columella straight, with numerous (eight to twelve) triradiate verticils of ascending lateral branches, which are inserted in the shell-wall.
Probably all those eradiate Sethocorida have been derived either from triradiate Sethopilida (Lychnocanium), or from multiradiate Sethophormida (Sethophormis, Anthocyrtis ?
Columella with four to six triradiate verticils, as long as the stout triangular pyramidal horn.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "triradiate" in a variety of sentences. We hope that you will now be able to make sentences using this word.
