REPOKT ON THE RADIOLARIA. 1431 



17. Tlieocapsa schwannii, u. sp. 



Shell slenderly ovate, or pear-shaped, with two distinct strictures. Length of the three joints = 

 1 :2 : 7, liveailth = 2 : 4 : 7. CephaUs siibspherical, small, with a stout, pyramidal horn of three 

 times the length. Cavity of the thorax subspherical, its thick wall with small, regular, circular, 

 hexagonaUy-fi'amed pores. Abdomen very thick-walled, with crested bars, and very large, 

 irregular, roundish pores. Basal pole rounded, truncate. 



DimcTisions. — Length of the three joints, a 0'02, b 0'04, c 014 ; breadth, a 0'04, h 0-08, c 014. 



Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 



18. Tlieocapsa mulleri, u. sp. (PI. QQ, fig. 7). 



Shell slenderly ovate, or pear-shaped, spiny, with two indistinct strictures. Length of the three 

 joints = 1:2:3, breadth =1 : 2 : 3. Cephalis ovate, with a stout, pyramidal horn of the same 

 length, and with a variable number of smaller accessory horns. Pores irregular, roundish, three 

 to four times as broad in the inflated abdomen as in the thorax. Basal pole hemispherical, spiny. 



Dimensions. — Length of the three joints, a 0*03, b 0-05, c O^OQ ; breadth, a 0'03, b 0'07, c 0'09. 



Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 



19. Tlieocapsa sarsii, n. sp. 



Shell pear-shaped, with two indistinct strictures. Length of the three joints = 1 : 1 : 3, breadth 

 = 1:2:4. Cephalis with a thick horn of the same length, conical. Abdomen subspherical, very 

 thick-walled, its pores regular, circular, twice as broad as the bars, and three times as broad as 

 those of the thorax. Basal pole flat, rounded. 



Dimensions. — Length of the three joints, a 0'04, b 0'05, v 0'12 ; breadth, a O'Oo, b O'll, c 015. 



Habitat. — Fossil in Barbados. 



20. Tlieocapsa darivinii, n. sp. (PL QQ, fig. 12). 



Shell pear-shaped, with two distinct strictures. Length of three joints = 1:1:5, breadth = 

 1:2:5. Cephalis hemispherical, with a conical horn of twice the length. Thorax campanulate, 

 with small, regular, circular pores. Abdomen broad, ovate, with larger, regular, circular, hexagon- 

 ally-framed pores. Basal pole hemispherical. 



Dimensions — Length of the three joints, a 0'03, b 0"04, c 0-2 ; breadth, a 0-04, b 0'08, c 0-2. 



Habitat.~C%iAm\ Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. 



Genus 624. Tricolocapsa,^ Haeckel. 



Definition. — T heocapsida (vel Tricyrtida eradiata clausa) without apical horn, 

 with a terminal lattice-plate on the mouth. 



' 3Vtcoiocapsa = Three-jointed capsule ; t;;«5xo», >ta4'«. 



