THE SPONGES. 



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thing more than f the total length. Very rarely a spicule is found 

 intermediate in size and character between these and the smallest indu- 

 bitable specimens of the elongated macramphidisc, which measure about 

 110 /x in length, and themselves are not common. 



In the small amphi- 



discs, up to lengths of 50 /x, it is only possible to count the umbel rays 

 with accuracy, in apical or approximately apical view. In such view it 

 may often be seen that the number of rays is more than 8, being in the 

 neighborhood of 14. 



At the extreme lower end of the specimen acanthophorae are found 

 in considerable abundance. They include diactines, tauac tines, and staurac- 

 tines, in which the ends are spinose, and commonly rounded and enlarged, 

 although sometimes pointed. In the tauactines and stauractines the rays 

 are subequal or very unequal, 12 to 16 /x thick, and commonly less — often 



much less 



than 200 /x in length. 



I have examined preparations of Schulze's type, and find that the only 



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tangible point of difference between the two sponges is the difference in 

 the length of the distal rays of the dermal pinules. On the other hand, 

 the dermal pinules, the two forms of macramphidisc, and the micro- 

 oxyhexacts, have in the two sponges the same character, even as to many 

 minute details of structure, such as the sudden curving exhibited by the 

 rays of the micro-oxyhexact. 



The type specimen was taken to the west of Prince of Wales Island 

 (55° 20' N.. 136° 20' W.), at a depth of 2869 metres on a muddy bottom. 



Hyalonema peduneulatum, sp, no v. 



Plate 3, Figs. 1-6. 



Diagnosis. Body pipe-shaped, produced below into a peduncle bene upon the body. 

 Gastral surface deeply concave. Canals very small, and consistency dense. Dermal and 

 gastral pinules with bushy distal ray, 320-440 /x long, ending above in a cone. Micro- 

 oxyhexacts with straight or slightly curved, minutely denticulate rays, 50-60 p long. 

 Macramphidiscs of one kind, 120-180 /x long, with wide umbels, which nearly reach the 

 equator of the spicule. 



Station 3JfUf> one specimen. 



The lower part of the sponge (Plate 3, Fig. 5) forms a peduncle-like 

 process, strongly bent upon the morphological vertical axis of the body. 

 -Ihe peduncle was broken across at a short distance from the body, the 

 actual lower end of the sponge not being present. The upper or gastral 

 surface exhibits a deep, narrow concavity, shown in sectional view in the 







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