Mr. H. J. Carter on the Lithistidse. 437 



LIV. — On the HEXACTiNELLlDiE and Lithistidm generalli/, 

 and particularly on the Aphrocallistidae, Aulodictyon, and 

 Farreas, together with Facts elicited from their Deciduous 

 Structures^ and Descriptions respectively of Three Neio 

 Species. By H. J. Carter, F.R.S. &c. 



[Concluded from p. 373.] 



following is a similar list of those also that have been brought 

 to notice. 



Lithistidse*. 



General character. Spicules developed upon a quadriradiate 

 division of the central canal, held together by amorphous 

 sarcode and an interlocking of their filigreed arms, forming 

 a reticulated glassy structure, whose interspaces are more or 

 less irregular and curvilinear. Composed of two kinds of 

 " skeleton-spicules," viz. those which form a layer on the 

 surface and are accompanied by minute or " flesh-spicules " 

 characterizing the species, and those forming the body, which 

 are more or less alike in all the species and accompanied by 

 fewer flesh-spicules. The skeleton-spicules of the surface, 

 which, for the most part, are provided with a smooth, pointed, 

 vertical shaft, directed inwards, and a horizontal head of dif- 

 ferent shapes according to the species, will be termed " surface-;" 

 and the spicules of the body, which interlock with their neigh- 

 bours through a filigreed development of all the arms, will be 

 termed " body-spicules." 



Species in which the surface-spicule consists of a shaft and three 

 straight bifurcated arms all smooth and pointed. 



Minute spicules of two kinds, viz. one acerate, fusiform, 

 slightly curved and microspined ; the other subspiral, sinuous, 

 tuberculo-spined. 



Dactylocalyx Bowerbankii, Johnson. Azores. (1) 



Masoni, Bowerbank. Madeira. (2) 



Corallistes typus, Schmidt. Florida. (3) 



♦ Abbreviations the same as in footnote, p. 357. 



1. B.M. P. Z. S. 1863, p. 259,=P. Z. S. 1869, p. 94, pi. vi. figs. 6, 7, & 8, 

 =MacAndrewia azorica, Gray, P. Z. S. 1867, p. 507. 



2. P. Z. S. 1869, p. 91, pi vi. figs. 1-4. 



3. Atlantisch. Spongienf. pi. iii. f. 3. 



4. B.M. P. Z. S. 1868, p. 565, fig. 1. 



5. P. Z. S. 1869, p. 89, pi. v. figs. 6-11. 



