10 PEOCEEDINGS OF THE ACADEMY OF 



anchor threads of Euplectella. It is evidently a different sponge from either 

 of those just named, and may be called Pheronema. 



The body of the sponge is oblong ovoidal, with the narrower end upward, 

 and with one side more prominent than the other. The lower extremity is 

 rather cj'lindroid and rounded truncate. The upper extremity is conical, with 

 a truncate apex presenting a large circular orifice. This is about 4 lines in 

 diameter and is the exit of a canal which descends in the axis of the sponge 

 for almost half its depth, and then appears to divide into several branches. 

 The sides of the sponge form thick dense walls to the cylindrical canal, which 

 is of uniform diameter before its division. 



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

 liibits an intricate interlacement of stellate, siliceous spicule, including a tissue 

 of finer spiculie of the same character, the whole associated by the dried re- 

 mains 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 distinct or 

 separate tufts of siliceous spiculae, looking like tufts of blonde human hair. 

 In the specimen there are fifteen tufts projecting around two-thirds of the ex- 

 tremity of the sponge, but the remaining third of the extremity of the latter 

 exhibits about ten 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 spiculae 

 2 inches. The coarser stellate spicules of the surface of the sponge in gene- 

 ral have five rays, of which four are irregularly cruciform, while the fifth pro- 

 jects at a right angle to the others towards the interior of the sponge. The 

 rays of the contiguous crosses form together a lattice work on the surface of 

 the sponge, and the intervals are covered by the rays of the finer spicula; which 

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

 terior 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 attenuated towards both ex- 

 tremities, 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 Euplectella, but have only two instead of four hooks at the end. 

 In the specimen but few of the spicules present the complete character as de- 

 scribed, 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 w'ould apper to be to maintain the position 

 or preserve the anchorage of the sponge in its ocean home, and perhaps in the 

 living animal they are incessantly produced as occasion may require, just as a 

 Mytilus or a Pinna renews and attaches its threads of byssus to secure its 

 position. 



The siliceous spicules of Pheronema are composed, as in sponges generally, 

 of concentric layers, and exhibited a delicate tubular axis. A spicula from 

 one of the tufts measured as follows: — 



Spread of the anchor one-tenth of a line ; shank of the anchor one- thirtieth 

 of a line ; prickled portion of shaft one-fortieth of a line ; shaft where thick- 

 est and without prickles one-eighteenth of a line, thinning out to the inserted 

 end where it was not more than l-30()th of a line. 



The species I propose to dedicate to my wife under the name of Pheronema 

 Annie. 



Dr. Leidy fur remarked, that if any of the members desired to examine 



