REPORT ON THE RADIOLARIA. 701 



triangular ; their base occupies about tlie middle third of each spine ; tlie proximal side of each 

 wing is the shortest, truncated or concave. 



Dimensions. — Length of the spines 0'4 to 0'5, greatest breadth (diagonal of the middle leaf- 

 cross) 0-08 to 0-12. 



Habitat. — North Pacific, Stations 253 to 256, surface. 



10. XiiJihacantha platyptera, u. sp. 



Spines four-winged, nearly prismatic in the basal and distal jiarts. Apex truncated. Base 

 with smaU wing-cross. Four apophyses wing-shaped, very broad and thin, extremely delicate, of 

 irregular quadrangular or nearly rhomboidal form ; their base occupiies the middle half of the length 

 of the spines (second and third quarter). Very variable in form. Often the edges of the wing- 

 apophyses of the neighbouring spines seem to meet. 



Dimensions. — Length of the spines 0'2 to 0'3, greatest breadth (diagonal of the leaf-cross) 0'06 

 to 0-08. 



Eahitat. — Pacific, widely distributed. Stations 239, 253, 272, 288, &c., surface. 



11. Xvphacantha ciliata, n. sp. (PL 129, figs. 4, 5). 



Spines four-winged, prismatic in the basal and the distal third. Apex pyramidal, short. Base 

 with large leaf-cross. Four apophyses wing-shaped, nearly semicircular, with dentated edges and 

 rough spinulate or porous faces ; their base occupies the middle third of the length of each spine. 



Dimensio7is. — Length of the spines 0"2 to 0'3, greatest breadth (diagonal of the apophysial cross) 

 0-08 to 012. 



Habitat. — Tropical Atlantic, Stations 342 to 352, surface. 



12. Xiphacantha alata; HaeckeL 



Xipltacantlia alata, Haeckel, 1862, ilonogr. d. Radiol., p. 388. 



AcantJwmetra alata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 48, Taf. ix. 

 figs. 1-3. 



Spines four-winged, prismatic in the basal quarter, more slender in the distal half. Apex 

 simple pyramidal. Base with small wing-cross. Four apophyses wing-shaped, nearly semicircular, 

 with denticulated edges (and often also with spinulate faces); their base occupies the second quarter 

 of the length of each spine. 



Dimensions. — Length of the spines 0'3 to 04, greatest bi-eadth (diagonal of the apophysial cross) 

 0-05 to 0-06. 



Habitat.- — Mediterranean (Nice), Midler, (Portofino), Haeckel. 



Genus 331. Stauracantha,^ Haeckel, 1881, Prodromus, p. 465. 



Definition. — A strolonchida with four branched (but not latticed) apophyses 

 on each radial spine, opposite in pairs in the form of a cross. 



' /Stowrocant/ia = Cruciate spine ; arav^ii, oixtti/ix. 

 (ZOOL. CHALL. EXP. — PART XI,. — 1885.) Rr 96 



