248 DR. HINDE AISTD MK. HOLMES OK SPOISTGE-EEMAIKS 



Hyalonema (c). — PI. XY, fig. 16. Amphidisc with slender 

 sliaft (covered with stout spines and with a subcentral whorl of 

 spines), and with long, slender, narrow, pointed terminal rays, 

 the ends of which curve slightly outwards. Length o£ spicule 

 •17 ram., width across head-rays "045 mm., length of head-rays 

 •07 mm., thickness of shaft "005 mm. The summit-rays are 

 incomplete, the full number being eight at each end. This spi- 

 cule is of the same character as the large amphidisc in Hyalonema 

 depressum, Schulze (Chall. Eept. vol. xxi. pi. sxxv. fig. 4), but it 

 is distinctly smaller. 



Hyalonema (d). — PI. XV. fig. 17. Amphidisc with stout, 

 slightly tuberculated shaft, having a median whorl of small nodes. 

 The summit-rays are elongate, spatuloid, pointed at the ends and 

 incurved. There appear to be eight at each end. Summit of 

 spicule flattened, convex. Length of spicule ^21 mm., width 

 across rays '06 mm., length of head-rays '095 mm., thickness of 

 shaft "01 mm. 



Hyalonema (e). — PI. XV. fig. 18. Spicule with stout shaft, 

 armed with a few scattered tubercles ; the summit rays, about 

 six in number, are stout, short, and openly curved. Length of 

 spicule "31 mm., width across rays "1 mm., length of rays "OSS mm., 

 thickness of shaft '02 mm. This spicule is very similar in cha- 

 racter and dimensions to the large amphidisc in Hyalonema 

 Sieboldi, Grray (see Chall. E.ep. vol. xxi. pi. xxvii. fig. 7), but 

 instead of 8 it has only 6 summit-rays at each end. 



Hyalonema (f). — Pi. XV. fig. 19. Amphidisc with shaft having 

 some small spines in the central portion ; summit-rays, six at 

 each end, ligulate, evenly curved. Length of spicule ^09 mm., 

 width across rays '03 mm., length of rays '036 mm., thickness of 

 shaft '0067 mm. This form is distinctly smaller than those 

 described above. 



Hyalonema (g). — PI. XV. fig. 20. Amphidisc with robust 

 shait, smooth with the exception of a subcentral whorl of small 

 tubercles. The summit-rays, 8 at each end, are curved, spatulate, 

 and elongate, so that there is only a short central interspace 

 between them. Length of spicule "208 mm., width across rays 

 •09 mm., length of rays ^087 mm., thickness of shaft -015 mm. 



PI. XV. fig. 21. Small amphidisc, shaft slender, having a few- 

 spines in the central portion ; rays delicate, acutely pointed, and 

 evenly curved and elongate, so as nearly to meet in the centre. 

 There appear to have been from 10 to 12 rays at each end in 



