REPORT ON THE HEXACTINELLIDA. 399 



On the internal surface of the entire tubular skeleton there arc longitudinal and radial 

 plates alternating with grooves of equal breadth, while on the external surface the frame- 

 work is flatly expanded. The loose parenchjonalia are represented not only by very 

 delicate uncinates and by numerous small rough oxyhexacts, but also by numerous 

 oxyhexasters, with rather long strongly developed principal rays, each bearing two short 

 moderately divergent terminals, besides simple medium-sized oxypentacts. The dermal 

 skeleton contains scopulae, with four approximately S-shfipcd rough prongs, which are 

 at their extremities only slightly, or not at all swollen. The gastral skeleton contains 

 numerous similar scopulae, in which, however, the prongs are almost straight. There 

 seem to be no pentacts in the gastral skeleton. Japan. 



Species 2. Hexactinella lata, n. sp. 



Ramified strong-walled tubes, in which the branches, more than a thumb's breadth 

 in thickness, expand superiorly in funnel- or syringe-like fashion, and open by wide 

 terminal apertures several centimetres in width. In the longitudinally disposed radial 

 plates of the dictyonal framework, which alternate with grooves or canals of equal breadth, 

 and are especially distinct on the external surface of the tubes, it may be seen that the 

 dictyonal beams radiate from the inside and from below towards the exterior and 

 superior surface. On the surface of the predominantly square-meshed framework there 

 are minute tubercles, arranged for the most part in transverse rows. The loose paren- 

 chymal needles are represented by variously disposed weakly developed uncinates and 

 numerous thin oxydiacts, also Ijy small disco- or sphsero-hexacts, with cylindrical rays 

 and terminal knobs, by oxyhexasters with long thin terminals, and, lastly, by sphsero- 

 hexasters, with two to six simple straight or S-shaped terminals of medium length. 

 In the moderately large dermal and gastral pentacts there is usually a more or less 

 conspicuous rudiment of the sixth freely projecting radial ray. The dermal and gastral 

 scopulse have four knobbed, slightly divergent, rough prongs. Little Ki Island, 

 140 fathoms. 



Species 3. Hexactinella ventilabrum, Carter. 



A thick-walled cup, widely open above, and laterall}' somewhat compressed ; borne 

 by a broad firm base fixed to a solid substratum. The radial plates which extend 

 lietween the predominantly longitudinal and oblique canals, traversing the wall often in 

 curved courses, are more distinctly seen on the outer, than on the inner surface of the 

 skeleton. The beams of the predominantly square-meshed framework are sparsely beset 

 with minute irregularly distril>uted pointed tubercles. The loose parench}Tiialia are 

 represented not only by a few uncinates with slightly developed barbs, l)ut also by 



