126 
Length ca. 40 mm, thickness about 10 mm. Surface very uneven, 
because spicule-bundles raise the dermal-membrane to many very 
small conical prominences; spicula pierce the membrane in several 
places, making the surface hispid. Dermal-membrane very thin and 
transparent, so that the numerous subdermal-cavities can be seen. 
Consistence very soft, elastic. Colour grayish-white. 
Fig. 6. Reniera laxa, Ldbck., oxea and apex of same. — Fig. 7. Pachychalina densa 
nov. sp., oxea and strongyla. 
Skeleton consists of particularly thick fibres containing numer¬ 
ous spicules side by side; often the thickness of the fibre is 
stouter than the length of a spicule, and the spicules are very 
closely pressed together; spongin rather slightly developed, very 
difficult to observe. The fibres are connected with one another so as 
to form a very irregular meshwork with often very big meshes (up to 
1 mm in width); in the tissues between the fibres are lying several 
spicules, a great percentage of which are developmental forms. 
Spicules: (fig. 7) oxea to tornota, the overwhelming number 
of spicules however oxea; often the points are blunt, in cases so 
as to form strongyla; slightly bent at the middle in a soft curve; 
thickness over the greater part of the spicule even. Length vary- 
ing from 104 —145 p, thickness ca. 10—11 f.i. 
Size of spicules about the same as in P. caulifera Vosm.; Lund- 
beck gives 0,ii8 — 148 mm by 0,oo8—0,oi4 mm; only they are here 
generally somewhat shorter and thicker and are nearer to the tor- 
