All species have hollow appendices, or spines, with pointed tips. They can be either straight or curving with tapered ends. The exterior surface of the vesicle wall shows no modification in the areas concealed by the hollow appendices. Where no appendices are attached, the ornamentation of the parts is perfectly similar to those with the appendices removed. In the species that grow very short spines, as the above species, most spines are more or less massive. But as soon as the spines are longer and thinner...