BY E. F. KALLMANN. 545 



arising' secondary laniellfn? disposod in vertical planes; and mea- 

 sured, when complete, approximately 130 mm. in height l)v 120 

 and by SO nmi. i-espectively in the greatest and least diameters of 

 tlie cup-orifice, and from 2 mm. (at the margin) to about onmi. in 

 the thickness of the lamina or cup-wall.- it exists now in two 

 pieces, one of which — figured bv Whitelegge — is in a dried but 

 otherwise undamaged condition, wliile the other is well-preserved 

 in alcohol. According to the original description, the latri'al 

 lamella^ occur on both the inner and tlie outer surfaces of tlic 

 cup, but this is really not the case; they are confined entii'clv to 

 the interior side. J 



A second specimen (also obtained by the "Thetis" Expedition^ 

 l)ut from an unknown locality) is now known, which is simply 

 tlabelliform without sect)ndary outgrowths. This measm-es 

 90nnn. in height by only 2 to .3 mm. in thickness, and is in a 

 (h'ied, completely washed-out condition. 



An exceedingly characteristic feature, — very clearly e^■id':"!lt 

 wlicn the sponge is examined by transmitted light, — is the 

 sti'uctural peculiarity of the lamina, whicli is alternately denser 

 and less dense along slightly diverging, ever multiplying lines, or 

 rather sti'ips, running in a direction from stalk to maigin: along 

 the denser strips, the lamina is usually slightly thicker than it is 

 between them, and the surface is accordingly marked witli 

 radiating faint grooves and slight ridges. With respect to this 

 structure, however, the two specimens exhibit a very appreciable 

 dift'erence, which may prove to be varietally distinctive. In the 

 smaller specimen, the strips (of greater density) are all directerl 

 radially, increasing in number upwards by repeated branching, 

 and are all similar in (character; they diminish in individual 

 width from somewhat less than 2 mm. in proximity to the stalk 

 to less than 0'5 mm. at the sponge-margin, and the width of the 

 intervening strips of lesser density is about tlie same. In some 

 portions of the type-specimen, the structure is veiy similar to 

 this, except that the lines of greater density are generalh' much 

 broader; but elsewhere there also occur a few relatively very 

 powerful, dense, nervure-like thickenings of the lamina, ramify- 



43 



