the ^Challenger ' Monaxonida. 337 



Subfamily v. Vomerulina. 



Characterized by the presence of a trenchant biharaate 

 spicule *. 



Genus Vomerula (Schmidt). 



Skeleton-spicules acuate. Flesh-spicules large trenchant 

 bihamates, to which others may be added. 



Vomerula esperioides^ n. sp. 



Erect leaf-like expansions, up to 10 inches high. Pale 

 yellow. Surface uneven, conulose. Dermal membrane thin 

 and transparent, with well-marked skeleton reticulation ; sub- 

 dermal cavities large and irregular. Texture tough and 

 coarsely fibrous. .Vents upon small thin-walled tubular 

 projections. Spicules : — (1) smooth acuates, size '7 by -019 

 millim. ; (2) large trenchant biliamates, contort, notched at 

 the inner angles and in the centre of the shaft, as in Bower- 

 bank's figure {l. c), length -177 millim., breadth of shaft 

 •019 millim. ; (3) small bihamates of the usual kind, length 

 •038 millim. 



Localities. Station 142, Agulhas Bank, Cape of Good Hope, 

 150 fath., abundant; Station 320, oflf Rio de la Plata, 600 

 fatli., one fragment. 



Family 3. DesmacidonidaB. 



Skeleton-spicules of various forms. Anchorate flesh- 

 spicules normally present. 



Subfamily i. Esperina. 

 Fibre not echinated by laterally projecting spicules. 



Genus EsPERELLA t (Vosmaer) . 



Skeleton-spicules smooth, acuate to spinulate. Flesh- 

 spicules palmate inequianchorates, to which may be added 

 bihamates &c. Main skeleton with conspicuous primary 

 fibres. 



Esperella mammiformisy n. sp. 

 Sessile, hemispherical, about | inch in diameter, with short 



* Vide Bowerbank, Mon. Brit. Spong. vol. i. pi. v. fig. 112. 

 t Esperin, Nardo. 



