168 THE VOYAGE OF H.M.S. CHALLENGER. 



Dimensions. Diameter of the whole shell - 22 ; distance between each two shells 0'02 ; length 

 of the by-spines 0'05, of the main spines 0'2. 



Habitat. Indian Ocean, Cocos Islands, surface, Eabbe. 



Subfamily STAURODORIDA, 1 Haeckel, 1881, Prodromus, pp. 449, 455. 



Definition. S taurosphserida with spongy, spherical shell (with or without en- 

 closed concentric lattice-shells). 



Genus 71. Staurodoras, 2 Haeckel, 1881, Prodromus, p. 455. 



Definition. S taurosphserida with solid, spongy, spherical shell and four crossed 

 simple spines. 



The genus Staurodoras may be developed from Styptosphara by the production of 

 four crossed spines on the simple, spongy, spherical shell, which is composed of looser 

 or denser irregular wicker-work, without enclosed medullary shell. 



1. Staurodoras spongosphcera, n. sp. 



Four crossed spines, two to three times as long as the diameter of the spongy sphere, three-sided 

 prismatic, with three dentated and spirally contorted edges. (Form of Spongosphcera streptacanlha, 

 but without medullary shell and with four equal spines, crossed regularly at right angles.) 



Dimensions. Diameter of the sphere 0'25 ; length of the spines 04 to 0'7. 



Habitat. Central Pacific, Station 271, surface. 



2. Staurodoras mojsisovicsi, Dunikowski. 



Staurodoras mojsisovicsi, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 28, 

 Taf. v. fig. 56. 



Four crossed spines, one and a half times as long as the diameter of the spongy sphere, three- 

 sided pyramidal, with three smooth edges. (What Dunikowski describes as " inner canals " of the 

 spines are their edges.) 



Dimensions. Diameter of the sphere 0~14 ; length of the spines 0'18 to 0'2, basal breadth 0'04. 



Habitat. Fossil in the Alpine Lias (Schafberg near Salzburg). 



3. Staurodoras liassica, Duuikowski. 



Staurodoras liassica, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 28, 

 Taf. v. fig. 57. 



Four crossed spines, shorter than the diameter of the spongy sphere, conical or pyramidal (?). 

 Dimensions. Diameter of the sphere 0'19 ; length of the spine 013, basal breadth 0-045. 

 Habitat. Fossil in the Alpine Lias (Schafberg near Salzburg). 



. * Staurodorida = Staurosphserida spongiosa = Spongospheerida tetracantha. 

 1 Staurodoras = Crossed spear ; aravjo'r, 



