26o DISCOVERY REPORTS 



quadriradiates forming skeleton of chamber layer and a layer of large rhabds immediately 

 beneath gastral surface; rhabds simi- 

 lar to those of gastral layer found pro- 

 jecting, sparingly, from dermal surface ; 

 triradiates of dermal tangential layer, 

 equiangular and equiradiate, rays o-i8 

 by o-oi mm.; quadriradiates of cham- 

 ber layer, apical rays o-i8 by o-oi mm. 

 and basal rays 0-28 to 0-42 by 

 0-024 "^rn- ' rhabds 0-59 by 0-022 mm. 

 Remarks. The holotype is no more 

 than I cm. high and 2 mm. in diameter. 

 To have described adequately the spi- 

 cules of the oscular margin, according 

 to custom, would have meant the total 



Fig. 4. Leucaltis gastrorhahdifera, sp.n. Section of body 

 wall to show arrangement of skeleton (semi-diagrammatic) . 



destruction of the specimen, and since these spicules are not of diagnostic importance, 

 no attempt has been made to examine them. 



Fig. 5. Leucaltis gastrorhahdifera, sp.n. a, rhabd; b, sagittal 

 quadriradiate; c, dermal triradiate. x 150. 



The present species differs from the only other known species of the genus, L. 

 clathria, Haeckel, in external form, in the absence of small radiates from the gastral and 

 chamber layers, and in the presence of the large rhabds. 



