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



apertures ; twenty larger dimples in the centre of the plates (each with a couple of 

 aspinal pores) and fifty to one hundred or more smaller dimples, each of which contains 

 one sutural pore. No blind dimples between the perforated dimples. 



1. Ceriaspis lacunosa, n. sp. 



Shell spherical, with seventy-two funnel-shaped dimples, each of which is perforated^on the 

 bottom by one or two apertures ; twenty larger dimples in the centre of the plates, each with 

 two elliptical aspinal pores, and fifty-two smaller sutural dimples between them, each with one 

 circular pore of half the size. No blind dimples. Radial spines quadrangular, stout ; their outer 

 part shorter than the inner. 



Dimensions. Diameter of the shell O'l, of the forty parmal pores O'Ol, of the fifty-two sutural 

 pores 0-005. 



Habitat. South Atlantic, Station 330, surface. 



2. Ceriaspis scrobiculata, n. sp. 



Shell spherical, with seventy-four funnel-shaped dimples, each of which is perforated on the 

 bottom by one or two apertures ; twenty larger dimples in the centre of the plates, each with 

 two kidney-shaped large pores, and fifty-four smaller dimples on the sutures, each with one circular 

 pore of one-fourth of the size of the reniform pores. No blind dimples. Radial spines cylindrical, 

 the outer part longer than the inner. 



Dimensions. Diameter of the shell 012, of the forty parmal pores 0'016, of the fifty-four 

 sutural pores 0'004. 



Habitat. Central Pacific, Station 270, surface. 



Subgenus 2. Ceriaspidium, Haeckel. 



Definition. Shell-surface with funnel-shaped dimples (commonly one hundred and 

 seventy-six or one hundred and eighty-two), which on the bottom are partly closed, 

 partly perforated by one aperture (or by a pair of pores). The blind dimples are 

 placed on the corners of the twenty plates, and are therefore either one hundred and four 

 or one hundred and eight ; if there be no polar suture, the blind dimples are one hundred 

 and four (twenty-four on the four hexagonal equatorial plates, forty on the eight penta- 

 gonal tropical plates, and forty on the eight pentagonal polar plates); if, however, there 

 be a polar suture on both main poles, the number of blind dimples is one hundred and 

 eight (twenty -four on the four hexagonal equatorial and twenty-four on the four hexa- 

 gonal polar plates, two opposite on each pole ; forty on the eight pentagonal tropical 

 plates and twenty on the four pentagonal polar plates, two opposite on each pole). 

 Between the blind dimples there are usually seventy-two to seventy-four perforated 



