J. G. WALLER ON A NEWLY DISCOVERED BRITISH SPONGE. 219 



kind of duplicate flange, only to be expressed in the given 

 figure. (Figs. 6, 7, 8, 9.) There are also a few arcuate entirely 

 spined forms of spicules, projecting through the membrane ; the 

 spines are minute, but more developed at the base : these are very 

 sparsely distributed. (Fig. 10.) Lastly comes the curious and novel 

 shape, also in the reticulation of the membrane, and intermingled 

 with it. It is in the form of forceps, as sugar-tongs, or more nearly 

 a lady's hair-pin. The shafts are cylindrical and equal throughout, 

 incipiently spinous, but very slightly denned, giving a somewhat 

 uneven look to the whole, and they are rounded at the terminations, 

 where in some specimens they slightly diverge from the straight 

 line. At what may be called the spring of the forceps is a bulbous 

 heart-shaped development, but this is only found on one side. (Figs. 

 11, 12.) This form averages in length about 6-4000ths of an 

 inch. It is sparsely distributed, but is more numerous than 

 the large bihamate or the spinous arcuate spicule, and some 

 embryonic forms are here and there to be seen developing 

 on the membranes. (Fig. 13 a.) None such has before 

 been discovered in the s23onges, but an instance of a forcepi- 

 form shape is figured by Dr. Bowerbank (Vol. iii., PI. XLIIL), 

 as belonging to his species Halichondria forceps. In this, 

 however, the shafts are long and unequal, and it is entirely spined . 



Exotic sponges give us some varieties of the forcepiform spicule. 

 In the " Annals and Magazine of Natural History," 4th Series, 

 Vol. xiv., Mr. Carter figures and describes two examples. One is 

 from a sponge found in the dredgings of the " Porcupine," from the 

 Atlantic Ocean ; another from an arenaceous dredging near Colon or 

 Aspinwall, Panama. The first is from a sponge named Esperia 

 cupressiformis, and the forcepiform spicule is described (p. 248) as 

 very minute, and having bulbous inflations at the extremity of each 

 arm (fig. 15). The second was obtained by Mr. F. Kitton from the 

 dredging above-named, and Mr. Carter names the sponge from which 

 it issued, though unknown, Forcepia colonensis (Fig. 16). 



The figures given in PI. VIII. are copies from those in the 

 " Annals." There is also another form I have met with in a curious 

 sponge, which constructs its network of an indiscriminate mixture 

 of extraneous spicules, either whole or fragmentary. I am 

 ignorant of the sponge from whence it came, but it is given 

 in Fig. 15. Mr. Carter also gives the forcepiform spicule of 

 H. forceps (Bowerbank) ; and he alludes to having found a minute 



