Page:Scientific results HMS Challenger vol 18 part 2.djvu/490

1366 These apophyses exhibit a remarkable variety in the great subfamily Theophormida, with open mouth. In the small subfamily Theophænida, however, the apophyses appear as six or nine simple lateral wings on the abdomen.

The Theophormida are richly represented not only in the present seas, but also as fossils in Barbados, and numerous remarkable forms have been already described by Ehrenberg, in his genera Calocyclas and Cycladophora. Many Phormocyrtida belong to the most elegant and admirable forms of Radiolaria.

Definition.— with the basal mouth of the shell open (vel Tricyrtida multiradiata aperta).

Definition.— (vel Tricyrtida multiradiata aperta) with numerous radial ribs enclosed in the wall of the thorax and of the flat dilated abdomen; mouth of the latter wide open.