EEPORT ON THE RADIOLAHIA. 639 



Dimevsions. — Length of the central chamber 0'04, breadth 0-025 ; length of the lateral girdle 

 0-11, breadth 0-08 ; height of the gates 003, breadth 0-04. 



Habitat. — Mediterranean (Genoa), Haeckel, (Messina), K. Hertwig, surface ; Tropical Atlantic, 

 Station 348, surface. 



7. Trizonium staurohelonium, n. sp. 



Central chamber spherical, with two opposite polar beams. Lateral girdle eHiptical, one and a 

 half times as long as broad. Four gates transverse-eUiptical, half as high as broad. Ten to eleven 

 pores on the half equator, fourteen to fifteen on the half meridian. Four conical radial spines, two 

 on the poles of the lateral, two on the poles of the principal axis. 



Dimensions. — Diameter of the central chamber 0-02 ; length of the lateral gu'dle 0-075, breadth 

 0-05 ; height of the gates 0-014, breadth 0-028. 



Habitat.— ^orih Pacific, Station 241, depth 2300 fathoms. 



8. Trizonmin hexabelonium, n. sp. 



Central chamber elliptical. Lateral girdle hexagonal, one and a half times as long as broad. 

 Four gates rhombic, two-thirds as high as broad. Eight to nine pores on the half equator, twelve to 

 thirteen on the half meridian. Six radial spines in the lateral plane, opposite in pairs on the six 

 corners of the lateral girdle (two principal and four diagonal). 



Dimensions. — Length of the central chamber 0-024, breadth O'OIS; length of the lateral girdle 

 0-06, breadth 0-04 ; height of the gates 0-02, breadth 0-03. 



Haiitat. — Pacific, central area, Station 263, depth 2650 fathoms. 



9. Trizonium octohelonium, n. >sp. 



Central chamber eUiptical. Lateral girdle hexagonal, one and one-third times as long as broad. 

 Four oates kidney-shaped or nearly rhombic, twice as broad as high. Eleven to twelve pores on the 

 half equator, sixteen to seventeen on the half meridian. Eight radial spines, opposite in pairs in 

 two crossed diao'onal planes. (Au intermediate stage between Dizo7iium odacantlrum and A^iqjhijiyle 



octostylc.) 



Dimensions. — Length of the central chamber 0-03, lireadth 0-024 ; length of the lateral girdle 

 0-09, breadth 0-07 ; height of the gates 0-025, breadth 0-05. 



Habitat. — Indian Ocean, Madagascar, Piabbe, surface. 



10. Trizonium decabelonium, n. sp. 



Central chamber eUiptical. Lateral girdle hexagonal, one and a half times as long as broad. 

 Four "ates rhombic, twice as broad as high. Twelve to thirteen pores on the half equator, seventeen 

 to eif'hteen on the half mericUan. Ten radial spines, two opposite on the two poles of the principal 

 axis, eight others opposite in pairs in two crossed diagonal planes. 



