408 



THE VOYAGE OF H.M.S. CHALLENGER. 



in. Hijaloucma — continued. 



5 Eody egg-shaped. The gastral pinuli have a long thick, 



spindle-shaped swollen radial ray, with short lateral 

 teeth. Terminal umbels of the large amphidiscs are 

 arched, ...... 



Body exactly spherical, with firm dermal skeleton. The 

 gastral pinuli have a thin radial ray, with short, 

 curved, lateral spines. Terminal umbels of the 

 large amphidiscs are conical, 



6 Both kinds of parenchymal oxyhexacts, or only those 



with straight rays bear lateral spines on the rays, . 



All the parenchymal oxyhexacts have exclusively smooth 



rays, ...... 



7 The lateral spines on the rays of the parenchymal oxy- 



hexacts have their j)oints directed towards the 

 centre. Oscular sieve-plate present. 



The lateral spines on the rays of the parenchymal oxy- 

 hexacts are directed towards the exterior. Oscular 

 sieve-plate present, .... 



The lateral spines are inserted at right angles to the 

 straight rays of the parenchymal hexacts, . 



8 Body of an exactly conical form. Large amphidiscs occur 



with very broad terminal umbels and broad smooth 

 marginal rays. An oscular sieve-plate is present, . 



Body more or less swollen out. There are no large 

 amphidiscs, ..... 



9 The dermal pinuli bear short, strongly developed basal 



rays, ...... 



The dermal pinuli have long, slender, basal rays, 



10 The dermal pinuli have a very slender radial ray with 



apposed short lateral teeth and slender pointed 

 terminal portion. The straight, slender, long, lateral 

 teeth of the terminal truncated amphidisc-terminal 

 umbels diverge inwards. An oscular sieve-plate 

 is present, ...... 



^he dermal pinuli have somewhat long lateral teeth on 

 the distal ray. The terminal umbels of the larger 

 amphidiscs are deeply bell-shaped, . 



11 The dermal pinuli have a long, very thin, markedly 



pointed radial ray, with short closely appressed 

 lateral teeth. The large amphidiscs bear twelve to 

 thirteen lancet-shaped teeth onthemargin of the discs. 



PAGE AND PL.\TE 



H yalonema clavigeniiit, . 220 



XLI. 



Hyalonema globus, 



7 

 8 



Hi/alonema toxeres, 



10 

 11 



221 



XL. 



201 



XXIX. 



Hyalonema sieholdii, . 190 

 XXVII. 



Hyalonema diver gens, . 199 



XXVIII. 



Hyalonema lusitanicujii, . 225 



XXVIII., XXXIX. 



Hyalonema feniie, 



228 



XXX. 



