CALCAREA. 4 1 



The oscular rollar in thick and densely packed with spicules. On the inside arc 

 (juadriradiates lying tangentially with the Iwisnl rayg downwards, and outside are 

 triradiates. The rim, which has no fringe, is formed of tri- and <juadriradiatcs, with 

 oral angles of nearly 180. There is a diaphragm in one specimen. 



Spicules (Fig. 128). 



Oxea. There are three sorts of Oxea : 



(a) Large projecting oxea, straight for about two-thirds of their length, then 



bending smoothly to one side. The inner (straight) end tapers gradually 

 to a point The outer end is blunt, shaped like the end of a thumb. 

 Most of the oxea are alxmt the same size, 460ft long x 24 p. thick. 

 Maximum size, 640ft x 25 p. There arc a few smaller, imperfectly formed, 

 possibly young, oxea. 



The minute spined oxea scattered throughout the body and forming the flagellated 

 chamler skeletons are of two forms : 



(b) Straight, refringent, thin, slightly spined, 50ft x 2ft. 



(c) Curved, hastate, thicker and well spined, 50ft to 00 ft x 2*3 ft to 3'lft. 



The junction of the spear-head is marked by a ring of four or more large 

 spines. 



The Triradiates are of one aort : 



(rf) Alate triradiates from the dermal cortex and body-wall. These vary very 

 much in size and proportions. Most have the paired rays only slightly 

 shorter than the basal ray, but occasionally there is great disparity. Hasal 

 ray straight, tapering uniformly to a sharp point, 130ft to 330 ft long x 

 8 ft to 15 ft thick. Paired rays equal, nearly straight, but slightly 

 irregular, 90 ft to 320ft long x 8ft to 14 ft thick. Oral angle 108 to 115. 



(e) C/tiacthieft. Basal ray straight, tapering uniformly to a sharp point, 400 ft 

 to 580/x long x 14ft to 18ft thick. Paired rays straight, bluntly pointed, 

 160ft to 280ft long x 14ft to 16 ft thick. Oral angle 160. Angle of fold 

 155 to 165. Apical ray nearly straight, pointed, 100 ft long x 12 ft 

 thick. Set-over small. Angle Instwecn apical ray and Itasal ray 175. 



MEOATOGON CRISPATUS.* 

 (Plat* XXVII., Fig. 2, and Plate XXXVIIL, Figs. 131-136.) 



There are four specimens of this new species in the collection, all found together. 

 The sizes are 9 mm. x 3 mm. ; 6 mm. x 2 mm. ; 6 mm. x 3 mm. ; 4 mm. x 2 mm. 

 They are vase-shaped, white or pale orange as preserved in spirits, with a curly surface 



, early-haired. 



2 N 2 



