REPORT ON THE HEXACTINELLIDA. 317 



circular incurrent aperture of the funnel lies under the porous dermal membrane, while 

 the blind pointed apex lies somewhat in the middle of the space, and turned towards 

 the gastral membrane. 



While a section at right angles through the wall, which shows longitudinal sections 

 of the radial canals, exhibits the funnels in longitudinal or lateral section, that is to 

 say, affords a lateral view of a chamber system (PL LXXXIV. fig. 1), a view from 

 the dermal skeleton reveals in each of the hexagonal spaces, on the inner surface of the 

 skeletal enclosure, a circle of chambers which surround a simple, central, funnel-shaped, 

 space (PI. LXXXIII. fig. 4), and a view from the gastral surface into the wide, 

 excurrent tube, shows the septa which arise by the coalescence of the large diverticula 

 forming the funnel (PI. LXXXIII. fig. 3). 



3. Aphrocallistes vastus, n. sp. (PI. LXXXV.). 



The specimen represented on PI. LXXXV. fig. 1, in its natural size, was collected 

 by Dr. Doderlein in the Sagami Bay (Japan), from a depth of 180 fathoms. There 

 was also a small fragment firmly fixed to a Coral, and apparently of similar structure, 

 probably belonging to the same specimen. They represent parts of the lateral wall 

 of a large cup. Instead of the glove-finger-like sacculations which occur in Aphro- 

 callistes beatrix and Aphrocallistes bocagei, there is here a simple folding of the wall. 

 Whether the tolerably irregular, bulging folds, which are here and there attached to 

 the Coral branch were directed longitudinally or transversely to the axis of the entire 

 cup covdd not be certainly determined, though I am inclined to believe that they were 

 longitudinal. In this connection it is interesting that in another specimen of Aphro- 

 callistes bocagei, bought in Enosima by Dr. Gottsche, an indication of the longitudinal 

 folding of the cup-wall could be recognised. A trace of the same is also to be observed 

 in the figure of Aphrocallistes beatrix given by Gray. 



Since the thickness of the cup wall amounts to 5 mm., the mesh spaces, which are 

 about 1 mm. in width, have become canals, which penetrate the wall transversely in 

 a radial direction. The dermal membrane, which is still clearly visible in these dried 

 specimens, extends in the form of a delicate skin over the whole outer surface. With 

 a lens one can recognise a fine quadrate lattice-work formed of apposed dermalia. A 

 quadrate lattice-like network of this kind is indeed entirely absent on the inner side 

 of the partially-preserved gastral membrane, which has rather an irregular streaky 

 appearance. 



A more accurate examination of the dictyonal framework of the septa between the 

 radial six-sided prismatic canals, shows that it consists of a single-layered network, 

 w^ith meshes predominantly three- or four-sided. The beams of the network bear rays 

 directed at right angles or oblic|ue]y to the dermal surface, and projecting freely 



