1366 



THE VOYAGE OF H.M.S. CHALLENGER. 



These apophyses exhibit a remarkable variety in the great subfamily Theophormida, with 

 open mouth. In the small subfamily Theophsenida, 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 Cydadophora. Many Phormocyrtida belong 

 to the most elegant and admirable forms of Radiolaria. 



I. Subfamily 



Theophormida. 

 Terminal mouth of the 

 abdomen a simple 

 wide opening. 



II. Subfamily 



Theophsenida. 



Synopsis of the Genera of Phormocyrtida. 



Terminal mouth of the ab- 

 domen closed by a lattice- 

 plate. 



Six lateral wings, . 

 Nine lateral wings, . 



601. TheopJiormis. 



602. Phormocyrtis. 



603. Alacorys. 



604. Cycladophora. 



605. Calocydas. 



606. Clathrocyclas. 



607. Lamprocydas. 



608. Diplocydas. 



609. Hexalatractus. 



610. Theqphama. 



Subfamily 1. THEOPHORMIDA, Haeckel, 1881, Prodromus, p. 436. 



Definition. P hormocyrtida with the basal mouth of the shell open (vel 

 Tricyrtida multiradiata aperta). 



Genus 601. Theophormis, 1 Haeckel, 1881, Prodromus, p. 436. 



Definition. T heophormida (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. 



1 Theophormis - Divine basket ; feo;, 



