78 



mostly extending in paratangential and radial directions. Hexactines, increasing 

 in number towards the inner surface of the tube-wall, are associated with the 

 longitudinal beams. These hexactines vary in size, are mostly arranged radially 

 and joined to each other and to the beams by synapticula. The skeleton of the 

 inner part of the tube-wall, where the hexactines are more numerous, forms a 

 much less regular network with wider meshes than the skeleton of the outer parts 

 of the tube-wall, composed chiefly of joined beams. The skeleton of the lower 

 part of the peduncle is much stronger than that of its central and upper parts, 

 where the supporting spicules are not so stout and not so firmly joined by 

 synapticula. Here, in the upper part of the peduncle, a number of the hexactines 

 remain free and here also a few of the same discohexasters which occur in 

 the body parenchyme are met with. Finally, at the upper end, where the 

 peduncle widens out in a trumpet-shaped manner, the synapticula joining the 

 longitudinal beams become scarcer and less firm, the hexactines quite slender and 

 mostly quite free and the discohexasters numerous. Further up we find, on the 

 inner and outer surfaces of the tube-wall, the same layer of hypogastralia and 

 hypodermalia as on the surfaces of the sponge-body itself and so the peduncle 

 gradually passes into the body. 



Saccocalyx pedunculata was found in the central part of the Bay of Bengal 

 12° 20' N., 85° 8' E. in a depth of 3300 m. = 1803 fths. 



As there are no Asconernatidae in the " Investigator " collection we now come 

 to the Family 



III. ROSSELLID^ 



Sponges which generally have a caliculate or sack-shaped body and autoderm- 

 alia without pinule-like distal ray. 



Bathtdortjs F. E. Sch. 



The body has the shape of a thin-walled sack or tube. The microsclere 

 parenchymalia are oxyhexasters and the autodermalia tetractines and diactines, 

 rarely pentactines. 



Bathydorus levis, F. E. Sch. 

 Plate XIV, figs. 1-10. 



1895 Bathydorus laevis F. E. Sch. (corr. levis) in Abh. Prenss. Ak. 1895 pp. 57-59, Taf. VI, figs. 1-10. 



In the south-western part of the Bay of Bengal three sponges were brought 

 up at one haul, which so closely agree in their macroscopic and microscopic 



