RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 1 23 



In its present condition the sponge is of a light-brown hue. Its 

 surface exhibits an intricate interlacement of stellate, siliceous 

 spiculae, including a tissue of finer spiculae of the same character, 

 the whole associated by the dried remains of the softer sponge tissues. 

 More or less fine sand, especially at the lower end of the sponge, 

 appears to be introduced as an element of structure. 



From the lower end of the sponge there projects a number of dis- 

 tinct or separate tufts of siliceous spiculae, looking like tufts of 

 blonde human hair. In the specimens there are 15 tufts projecting 

 around two-thirds of the extremity of the sponge, but the remain- 

 ing third of the extremity of the latter exhibits about 10 orifices, 

 from which as many additional tufts appear to have been extracted, 



Length of the body of the sponge 4^ inches ; diameter at middle 

 22 lines, at lower end 15 and 17 lines, at upper end 8 lines. Length 

 of tufts of spiculse 2 inches. The coarser stellate spicules of the 

 surface of the sponge in general have 5 raj-s, of which 4 are irregu- 

 larly cruciform, while the fifth projects at aright angle to the others 

 towards the interior of the sponge. The rays of the continuous 

 crosses form together a lattice work on the surface of the sponge, 

 and the intervals are covered by the rays of the finer spiculae, which 

 also in general have a five-rayed stellate character. The finer tissue 

 in the interior of the sponge, seen through the lattice work of the 

 surface, contains a multitude of spicules which differ from the 

 others only in their minute forms. Some of the largest stellate 

 spicules on the surface of the sponge have a stretch of three-fourths 

 of an inch. 



The spicules of the tufts projecting from the sponge are two or 

 three inches in length and vary in diameter. They become attenu- 

 ated towards both extremities, but especially that inserted into the 

 sponge mass. Starting from the latter, they are at first smooth, 

 then finely tuberculate, the tubercles gradually become converted 

 into well marked recurved prickles or hooks, and finally the spicules 

 end in a pair of longer hooks, recalling to mind the arms of an 

 anchor. The spicules bear a near resemblance to those at the lower 

 extremity of Euplcdella, but have only two instead of four hooks at 

 the end. In the specimen but few of the spicules present the com- 

 plete character as described, most of them apparently having been 

 broken. 



The object of the tufts of spicules, with their recurved prickles 

 and anchor-like free extremities, in Pheronema would appear to be to 

 maintain the position or preserve the anchorage of the sponge in its 

 ocean home, and perhaps in the living animal the}^ are incessantly 



