858 THE VOYAGE OF H.M.S. CHALLENGES. 



the base of each spine four crossed aspinal pores, two opposite of which are much larger than the 

 two other pores. 



Dimensions. Diameter of the outer shell 0'09, of the inner 0'04. 



Habitat. South Pacific, Station 302, surface. 



Subgenus 3. Dorypeltonium, Haeckel. 



Definition. Free apopliyses of the radial spines branched, and forming perforated 

 shields by union of their anastomosing branches. 



6. Dorypelta lithoptera, n. sp. 



Apophyses of the long compressed radial spines with anastomosing branches ; each spine 

 bearing two free separated shields (each with two roundish aspinal pores). At the base 

 of each spine (in the network of the outer shell) two elliptical aspinal pores, larger than the other 

 pores. 



Dimensions. Diameter of the outer shell 0'09, of the inner 0'03. 



Habitat. North Pacific, Station 239, surface. 



7. Dorypelta tessaraspis, n. sp. (PI. 133, fig. 2). 



Apophyses of the long cylindrical spines with anastomosing branches ; each spine bearing a 

 single free shield with four crossed aspinal pores of equal size (on the margin of the shield twelve 

 to sixteen spikes). At the base of each spine (in the outer shell) four crossed aspinal pores, about 

 .as large as the other roundish pores. 



Dimensions. Diameter of the outer shell Oil, of the inner 0'05. 



Habitat. Central Pacific, Station 263, surface. 



8. Dorypelta dodecaspis, n. sp. 



Apophyses of the long two-edged spines with anastomosing branches ; each spine bearing a 

 single free shield with six to eight parmal pores (four crossed aspinal pores alternating with four 

 outer coronal pores), on the margin of each shield twelve to sixteen spikes. At the base of each 

 spine (in the outer shell) four crossed aspinal pores, about as large as the other irregular pores. 



Dimensions. Diameter of the outer shell O'l, of the inner 0'04. 



Habitat. North Pacific (off Japan), Station 235, surface. 



Genus 370. Stauropelta, 1 Haeckel, 1881, Prodromus, p. 468. 



Definition. P hractopeltida with four simple equatorial spines and sixteen 

 spines protected by external free apophyses (eight tropical and eight polar spines). 



1 Stauropelta = Cross-shield ; arav^os, Kihin. 



