SCYPHIDIUM NAMIYEI. 33 



whereas, from side to side in the middle of tlie compressed 

 body, it measures not more than 20 mm. across. Two separate 

 oscula of different sizes, lying side by side, occupy the upper 

 edge of the body. There is a clear indication of the two having 

 been formed from an originally single and narrow oscnlum by 

 the coming together and fusion of the oscular lips at one part, 

 in a way similar to the process which takes place at the bifurcat- 

 ing point of a Farrea-tnhe. The smaller of the oscula thus 

 formed occupies the end of a short tube which appears like a 

 branch from the sponge-body. 



In both specimens, there are present along the sharp oscular 

 edge some prostal needles, which are fine, short and quite incon- 

 spicuous, besides being irregularly distributed and isolated. Simi- 

 lar prostals also occur in quite small numbers in the upper part 

 of the lateral wall. They are in all cases diactins projecting to 

 the extent of 3 or 4 mm. at most. — In places there are to be 

 seen some isolated hypodermal pentactins apparently more or less 

 protruded beyond the dermal level. Whether tliis represents a 

 normal state or is the result of rough handling, I am at loss to 

 decide. 



On the whole the external surface may be said to be smooth. 

 To the naked eye it appears as if loosely frosted. Not until ob- 

 served under the hand-lens can the dermal latticework and the 

 hypodermal supports be seen with distinctness. The dermal 

 layer is in very close contact "svith the choanosome. — The subder- 

 mally situated entrances into the incurrent canals are small, 

 probably never more than 1^ mm. in width. 



The gastral surface is likewise smooth. It is continuously 

 covered throughout l)y a most delicate gastral layer, supported on 

 fine sinuous hypogastral strands. — The excurrent canalar apertures, 



