CALCAKEA. 29 



of unequal lengths, 180 /a to 430 m long X 10 m to 16 /x thick. Oral angle 

 about 135°. 



(d) Smaller alate triradiates from the tubar skeleton. Basal ray straight, 



tapering to a sharp point, 140 m to 260 m long x 8)u, to 10/* thick. 

 Paired rays nearly equal and straight, BOju, to 150ju, long x 8ja to lOjn 

 thick, slightly folded. Oral angle 130°. 



Quadriradiates. — There are two sorts of quadriradiates : — 



(e) Large quadriradiates from the gastral layer. Basal ray straight, tapering 



uniformly to a sharp point, maximum length 1,000 /x. x 9/i. to 12 /a. 

 Paired rays of unequal length, often slightly crooked, of irregular thick- 

 ness, bluntly pointed, 220 /a to 420 /a long x 11/u, to 13/i thick. Apical 

 ray sharply pointed, bent orally, about 80 /a x 12 /a. Oral angle 128° 

 to 138°. 

 (/) Chiactines. Similar to (d) with the addition of an apical ray 90 /a long x 

 6 /A thick, sharply pointed. These are not shown in the drawing of 

 spicules. 



Oscular spicules : — 



(g) Fine straight oxea from the fringe, 3 /a to 4 /a thick. All are broken off, so 

 their length is uncertain. Among them are a few stout oxea of the same 

 sort as (a). 



(A) Thin zigzag oxea lying tangentially near the oscule. 170 /a to 300 /a long x 

 3 /A to 4 /A thick, sharply pointed at both ends. 



(i) The edge is formed of small quadriradiates. Basal ray straight, tapering 

 to a sharp point, 130 /a to 200 /a long x 9 /a to 12 /a thick. Paired rays 

 nearly equal, considerably bent downwards, 90/Ato 150/a long X 9 /a to 12 /a 

 thick. Oral angle 150° to 160°. Apical ray short and sharp, about 

 4:0 jx long. 



Family STAUROREHAPHIDiE. 



Definition. — There is a distinct and continuous dermal cortex, completely covering 

 over the chamber layer and pierced by inhalent pores. There are no subdermal sagittal 

 triradiates nor conspicuous subdermal quadriradiates. The flagellated chambers vary 

 from elongated and radially arranged to spherical and irregularly scattered ones, while 

 the skeleton of the chamber layer varies from regularly articulate to irregularly 

 scattered, but there are always regularly disposed suhgastral chiactines. 



The above only differs from Dendy's definition of Grantiidse by the addition of 

 the words in italics. 



