Dr. J. E. Gray on the Arrangement of Sjjonges. 289 



crenated disk, aud at others are simple, subulate, with a more 

 or less spinulose surface, or each divided at the end into two, 

 three, or more linear branches, which are frequently dilated 

 at the end. 



In the paper in the ^Annals' above referred to I divided 

 the sponges of this suborder according to their external form ; 

 but in the 'Ann. & Mag. Nat. Hist.' 1872, x. ]). 134, I pro- 

 posed to divide them into two groups according to the form 

 of the free spicules ; and since then Mr. Carter has shown 

 the importance of the study of the minute free spicules, or 

 rosettes. 



They may be divided into three sections, as proposed in the 

 'Annals,' 1872, x. p. 134 :— 



1. The rosettes with the ends of the six rays divided into two, 



three, four, live, or many branches. Including Farreadce, 

 Dactijlocalycidce^ AplirocallistidxK^ Euplectelladm^ Gorhi- 

 telladie, Ashonernatldcp ^ and Grateromorpliadce (Ann. & 

 Mag. Nat. Hist. 1872, x. p. 134), and Rossella, Carter. 



2. The rosettes witli six rays ending in a radiating circular 



disk. CarteriadrPj Pteronemada'^ and Meyerinadce (Ann. 

 & Mag. Nat. Hist. 1872, x. p. 134). 



Mr. Carter figures many of the rosettes of these genera 

 (Ann. & Mag. Nat. Hist. 1873, xii. t. 13 & 15). 



3. The rosettes subcubical, the rays with three lobes at the 



end. Axidcc. 



I gave the name of Axos Cliftoni to Bowxrbank's figure 

 (B. S. fig. 197) of the spicule of this sponge ; and when Mr. 

 Clifton gave me a fragment of the sponge I described it (Ann. 

 & Mag. Nat. Hist. 1870, vi. p. 272) under the name oiEchino- 

 spongia australis ; but at p. 346 of the same volume I showed 

 that Axos Cliftoni should be adopted. Dr. Bowerbank has 

 since figured the specimen from which the fragment was taken 

 by Mr. Clifton under the name of Dictyocylindrus dentatus 

 (Proc. Zool. Soc. 1873, p. 321, t. xxix.), without referring to 

 his figm'c in his work on British sponges. 



Suborder III. Quinqueradiatospongia. 



Sponges with spicules of the quinqueradiate type in com- 

 bination Avitli the simple spicules of Leiospongia, and frequently 

 having multiradiate spicules and spicular spherules in combi- 

 nation with them, either scattered free in the flesh of the sponge 

 or forming an external bark to it. 



Tlie sponges of this suborder present very numerous com- 

 binations of spicules ; and the five-rayed spicules which form 

 the skeleton of the sponge frequently want the outer end of 



