REPORT ON THE EADIOLARIA. 831 



radial spines, each of which bears four crossed apophyses. The subfamily may be 

 divided into two different tribes, the Stauraspida and Lychnaspida. In the Staura- 

 spida either all twenty spines, or a part of them, bear no perforated plates, and the 

 shell is composed wholly or partially of the meeting branches of their apophyses. 

 In the Lychnaspida, however, the four apophyses of each single spine form, by reunion 

 of their recurved branches, a plate or shield with four crossed aspinal pores. The 

 Lychuaspida represent therefore a more developed stage in the shell-formation than 

 the simpler Stauraspida. Stauraspis, as the common ancestral form of both, may be 

 derived phylogenetically from Xipkacaniha or Stauracantha, which differ only 

 by the apophyses or branches of the apophyses not meeting. These branches (originally 

 eight on each spine) are either simple or again branched. 



Subgenus 1. Staurasparium, Haeckel. 



Definition. Apophyses of the spines simple, not branched; therefore each spine 

 with four sutural condyles. 



1. Stauraspis cructata, n. sp. (PI. 134, fig. 5). 



Radial spines thin, quadrangular, prismatic; outer and inner half nearly of equal length. 

 Central bases pyramidal, with wing-like edges fig. 5). Four apophyses of each spine simple, not 

 branched, with thin condyles. Large meshes of the shell ten to twenty times as broad as the 

 bars. This and the following species greatly resemble the simplest forms of Phractaspis 

 (PL 137, figs. 1, 2) ; they differ from these, however, by the equal size and distance of the four 

 branches of each spine, which thus form a rectangular cross. 



Dimensions. Diameter of the shell 01 ; breadth of the spines and bars 0002. 



Habitat. Central Pacific, Station 268, surface. 



2. Stauraspis xiphacantha, n. sp. 



Eadial spines stout, cylindrical in the inner half, conical in the shorter outer half. Four 

 apophyses of each spine simple, not branched, broad, with thick condyles. Meshes of the shell 

 six to eight times as broad as the bars. * 



Dimensions. Diameter of the shell 0'12 ; breadth of the spines and bars O'OOS to O'Ol. 



Habitat. South Pacific, Station 290, surface. 



Subgenus 2. Stauraspidium, Haeckel. 



Definition. Apophyses of the spines branched; therefore each spine with eight to 

 tw y enty or more sutural condyles. 



