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



a deer-horn, one-fourth to one-half as long as the radius of the shell. Some other small spines 

 irregularly scattered over the shell. 



Dimensions. — Diameter of the shell 012 to 0-16, of the smaller pores 0-001 to 0-004, of the 

 larger armed pores 0-016 to 0-024 ; length of the spines 0-02 to 0-04. 



Hahitat. — Central area of the Tropical Pacifie, Stations 2G6 to 272, depth 2425 to 2925 

 fathoms. 



Genus 36. Siphonosphcera} J. Miiller, 1858, Abliandl. d. k. Akad. d. Wiss. 



Berlin, p. 59. 



Definition. — C o 11 o s p h se r i d a with simple shells, the pores of which are pro- 

 longed into external simple radial tubuli with solid wall ; outer mouth of the tubuli 

 truncated, smooth. 



The genus SiphonosphcBru is, next to CoUosphcBra, the most common of all CoUo- 

 sphserida, and rich in difterent species ; all agreeing in the tubular prolongation of the 

 pores, and corresponding therefore to EthmosphcBra among the simple Liosphserida. 



Subgenus 1. Holosiphonia, Haeckel. 

 Definition. — All the pores or apertures of the shell prolonged into tubules. 



1. Siphonosphcera pansiphonia, n. sp. 



Shell a regular sphere, everywhere occupied by short, regular cylindrical tubes, aU of the same 

 size and form. Length of the tubules equal to their breadth and to the intervals between them. 

 Ten to twelve tubules in the half meridian of the shell. This most regular species is nearly aUied 

 to Collosphcera reffidaris, and may be derived from it by tubular prolongation of all the regular 

 pores. 



Dimensions. — Diameter of the shell O'l to 0-12, length and breadth of the tubules 0-005 

 to 0-006. 



Habitat.— Indi&n Ocean, Sunda Strait, Eabbe, surface. 



2. Siphonosphcera marginata, n. s]3. 



Shell a regular or subregular sj^here, occupied by numerous short cyhndrical tubules of different 

 sizes. Six to -eight tubules in the half meridian of the shell. Diameter of the tubules about equal 

 to their distance apart, but two to four times as large as their length. 



Dimension. — Diameter of the shell 0-1 to 14; length of the tubules 0-004 to 0-006, breadth of 

 the tubides and the intervals O'Ol to 0-02. 



Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 



' Siphonosphcera = Sp'heK with tube.s ; aifau, afai^a. 



