EEPOET ON THE RADIOLARIA. 1097 



is crossed by horizontal zygomatic bars (between the ascending orbital and the descending maxillary 

 bars). Lateral lattice-girdle narrow, with few large meshes. 



Dimensions. — Shell 0-24 long, 0-2 broad ; ring 0-09 long. 



Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 



5. Amphispyris subquadrata, n. .sp. (PI. 88, fig. 5). 



Shell compressed, nearly square, spiny, with slight sternal incision and two distinct transverse 

 strictures. Similar to the preceding species ; four pairs of irregular annular pores of nearly equal 

 size. Zygomatic ring complete. Lateral lattice-girdle narrow, with few large meshes. 



Dimensions. — Shell 014 long, 012 broad ; ring 0-06 long. 



Habitat. — Central Pacific, Station 285, depth 2275 fathoms. 



0. Amphispyris costata, n. sp. (PL 88, fig. 3). 



Shell compressed, nearly square, with slight sternal incision and two obliterated transverse 

 strictures. Similar to the two preceding species ; with four pairs of large annular pores, the two 

 middle of which (the orbital and nasal holes) are much larger than the superior (frontal) and inferior 

 (oral) holes. Zygomatic ring incomplete. Lateral lattice-girdle broad, with very numerous, smaU, 

 irregular, polygonal pores. 



Dimensions. — Shell 0'2 long, 016 broad ; ring 0-07 Ions. 



Habitat. — North Pacific, Station 244, depth 2900 fathoms. 



7. Amphispyris toxarium, n. sp. (PI. 88, fig. 7). 



Shell inflated, with deep sternal incision and two distinct transverse strictures. Similar to the 

 preceding species, but with deeper constriction and looser lattice-work. Four pairs of large, irregular, 

 annular pores, the central two of which are much larger. Zygomatic ring complete. Lateral girdle 

 broad, with iiTegular pores of very different size. 



Di^nensions. — Shell 0'2 long, 014 broad ; rino- 0-09 long. 



Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 



Genus 482. Tncolospyris,^ Haeckel, 1881, Prodromus, p. 443. 



Definition. — Androspy rida without free basal feet, with three distinct joints, 

 separated by two transverse strictures ; lattice-work of the shell complete, simple. 



The genus Tricolospyris has arisen from the preceding Amphispyris, its ancestral 

 form, by develoj)ment of lattice-work which completely closes the large open holes 

 remaining on the ventral and dorsal faces of the latter. 



1 JVicofosp2/"is= Wicker-basket with three joints ; rjixuAoj, nxv^if. 

 (ZOOL. CHALL. EXP.— PART XL. — 1886.) Er 138 



