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



List of the Species of Stylasterid^e Dredged by H.M.S. Challenger, with 

 Descriptions of New Species obtained and hitherto undescribed. 



Sporadopora, Moseley. 



Sporadopora dichotoma, Moseley. 1 



Dredged on one occasion only, but then in considerable abundance. 



Station 320. Off the Mouth of the Rio de la Plata. 600 fathoms. 



PUobothrus, Pourtales. 



Pliobothrus symmetricus, Pourtales. 



One specimen only obtained. 



Station 23. Off Sombrero Island, Danish West Indies. 450 fathoms. 



Errina, Gray. 



Errina labiata, Moseley. 



Several specimens obtained on two occasions. 



Station 320. Off the Mouth of the Rio de la Plata. 600 fathoms. 



Station 135. Off the Tristan da Cunha group. 90 to 150 fathoms. 



Distich opora , Lamarck. 



Distichopora irregularis, n. sp. (PI. XII. fig. 8, «). 



Distichopora irregularis, mentioned but not described (Phil. Trans. Roy. Soc, 1878, 

 part 2, p. 502). 



Ccenosteum of a light pinkish colour, branching irregularly, flabelliform ; branches 

 rounded but moderately flattened in the plane of the flabelluni, more compressed towards 

 their tips. Surface of the ccenosteum finely granular in texture. Lines of pores sometimes 

 placed on the flabellar edges of the branches, sometimes absent from these, and coursing 

 irregularly in curved lines over the faces of the branches, often joining one another at 

 various angles. Pore rows consisting of a median row of nearly circular-mouthed 

 gastropores, with very deeply-seated styles, and placed somewhat widely with an 

 interval of about their own width between them ; and of a row of elongate-mouthed 

 dactylopores also sparsely disposed on either side. The lines of the pore rows are slightly 

 channelled out in the surface of the ccenosteum. 



1 For references, &c, see the general list of species of Stylasterida?, p. 83. 



