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



Species 2. Hyalonema gracile, n. sp. 



The inverted pear-shaped, superiorly truncate, inferiorly pointed body, is hardly as 

 large as a plum, and forms a slender untwisted basal tuft without a Palyihoa encrusta- 

 tion. The delicate terminal sieve-plate extends freely over the gastral cavity, which 

 exhibits internally a central columella and four cruciately disposed radial septa. The 

 parenchyma contains small oxyhexacts with straight, or curved smooth rays. The large 

 amphidiscs have moderately long arched terminal umbels with eight rather broad lancet- 

 shaped rays. Philippines, 2225 fathoms. 



Species 3. Hyalonema divergens, n. sp. 



The body has the form of an inverted, not belly-shaped, bell with the maximum breadth 

 at the superior, transversely truncated end. Over the flat gastral cavity with its free 

 central columellar cone, a delicate latticed network extends transversely. The basal, 

 somewhat narrowed end gives off a bundle of rather straight and thick spicules, forming a 

 basal tuft without a Palythoa encrustation. The parenchyma contains small oxyhexacts, 

 some with straight, and others with curved smooth rays. The large amphidiscs have 

 terminal umbels with somewhat transversely truncated extremity. The moderately long, 

 but not very broad uml^el-rays, with parallel margins, are almost straight and diverge 

 rather markedly. Mid-Pacific, east of Maldon Island, 2425 fathoms. 



Species 4. Hyalonema toxeres, Wyville Thomson. 



The spherical body, which is puffed out in the young forms, bears on its pointed 

 inferior end a brush-like diverging basal tuft with encrusting Palythoa on its upper 

 portion. Free terminal sieve-plate. The parenchyma contains small oxyhexacts, some 

 with straight, and others with curved rays, of which the latter are beset vdth barbs. 

 Large, thick, somewhat curved diacts also occur. Large amphidiscs like those of 

 Hyalonema sieboldii. Near St. Thomas, West Indies, 390 fathoms. 



Species 5. Hyalonema kentii, 0. Schmidt. 



Funnel-shaped body, with the sieve-plate intruding into the gastral cavity. The 

 parenchyma contains small weakly developed oxyhexacts, some with straight, others 

 with curved, almost smooth rays. Large amphidiscs with broad hemispherical terminal 

 umbels, in which the eight rays are broad lancet-shaped plates. West Indies, 300 to 

 1500 fathoms. 



