164 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



Amblypneustes pallidtjs. Lamarck. 

 Supposed to be a variety of A. griseus, by Agassiz. It is dis- 

 tinguished by its violet color, on which the white tubercles stand 

 out with brilliant distinctness. I do not know the species, the 

 habitat of which stretches out from South Australia across the 



Pacific. 



Genus 6. — Holopneustes, Agassiz, 1841. 



General character of Amblypneustes, but, A. space broader than 

 I., owing to the peculiarity of porif. zone, which distinguishes 

 this genus. The pores have a regular vertical row at each side 

 between which they are packed closely, with apparent irregu- 

 larity. Spines like Amblypneustes, but swollen at the extremity. 



Holopneustes porosissimus, Lutken. 



Test globular, stout. Porif. zone broader than median A. 

 space. Pores forming an outer very regular vertical row, inner 

 row somewhat undulating, while the remaining space is appa- 

 rently filled with irregular pores. Spines short, stout, swelling 

 at extremity, coarsely striated longitudinally, forming lamellae at 

 the swollen extremity, but otherwise, the shaft is uniform in 

 width. Milled ring very prominent. Color, greenish at base, 

 red at tip. Color of test greenish blue, shading to violet in 

 median spaces. Tubercles of lighter colour. 



Habitat. — All South Australia, Tasmania, Bass' Straits. I have 

 seen no authentic specimen from E. Australia. 



Holopneustes inflatus, Lutken. 

 Porif. zones narrower than in preceding, in three well marked 

 vertical rows, the outside ones quite irregular, and the middle 

 somewhat undulating and disconnected. Test yellowish orange, 

 with zones of darker tint. I have never seen this species. 



Holopneustes purpurascens, Lutken. 

 The porif. zone is narrower than in either of the two previous 

 species. The middle line of pores forms zigzag lines, and the 

 outer row of pores is characterized by the great size of the inner 

 pore. The younger specimens are a beautiful violet color, and 

 the older ones a yellowish brown. I have not seen the species 

 which Mr. Agassiz thinks may be only a variety of H. porosissimus. 



