REPOET ON THE RADIOLAEIA. 299 



Dimensions. — Major axis of the ellipsoid 014, iiiinor axis Oil ; pores 0-012, bars 0-003 ; length 

 of the polar spines 0-07, basal breadth 0-012. (Diameter of the lost medullary shell 0-03 ?) 

 Habitat. — South Atlantic, Station 338, depth 1990 fathoms. 



Gen-US 127. EUipsostylus,^ n. gen. 



Definition. — E llipsida -with simjjle ellipsoidal shell, the main axis of which is 

 prolonged at both poles into two opposite spines of different size or form. 



The genus Ellipsostylus differs from Elli2:>soxiplius only in the unequal size or different 

 form of the polar spines, which in the former are equal. This difference does not seem 

 important at first, but in the further development it produces very singular and 

 strange forms. Theoretically it is always important, because the fundamental haplo- 

 polar form of the monaxon body becomes diplopolar by this differentiation. 



Subgenus 1. EUipsostyletta, Haeckel. 

 Definition. — Network of the shell regular, -with pores of equal size and similar form. 



1. EUip)Sostylus ornithoides, n. sp. 



Proportion of the major axis of the ellipsoid to the minor = 4:3. Shell thin walled, with 

 regular, circixlar meshes and hexagonal framework between them, like that of Xiphostylus favosus 

 (PL 13, fig. 4). Circular pores about as broad as the bars ; eight to nine on the half equator. 

 Sul-face smooth. Polar spines three-sided pyramidal, as broad at the base as a single hexagon ; 

 the longer spine as long as the major axis, the shorter half as long. 



Biviensions. — Longer axis of the ellipsoidal shell 0-16, shorter axis 0-12 ; jjores and bars 0-006 ; 

 length of the longer polar spine O'lG, of the shorter 0-08. 



Habitat. — North Pacific, Station 241, depth 2300 fathoms. 



2. Ellipsostylus avicularis, n. sp. 



Proportion of the major axis to the minor = 3:2. Shell thick walled, with regular, rosette- 

 shaped meshes, three times as broad as the bars ; ten to twelve on the half equator. Every mesh 

 on the outer margin with five to six rounded lobes, as in Xipliostylus pJiasianus (PI. 13, fig. 9). 

 Surface smooth. Polar spines shai-p edged, thick ; the longer straight and equal to the longer axis, 

 the shorter half as long, shaped like a bird's head. 



Dimensions. — Longer axis O'lS, shorter axis 0-12 ; pores 0-015, bars 0-005. 



Habitat. — South Pacific, Station 300, depth 1375 fathoms. 



1 Ethpsostylus -WiiTp^oid with styles ; (Khu-<^i;, ari'hii;. 



