explanation of the plates. 683 



Plate LIV* 



Fig. a. Leuealtis hathyhia, var. masearenica, the two forms of stout 

 quadriradiate and the triradiate spicules of the main 

 skeleton, x38. a'. The minute tri- and quadriradiates 

 of thev oloacal surface, X 370. From type specimen from 

 Seychelle Islands. 



6. Axinella spieulifera, two sizes of the skeleton- spicule, x 68. 

 From specimen from Darros Island. 



c. A. proliferans, the skeleton-spicule, x 68. From type 



specimen from Providence Island. 



d. Lfiucortis anguinea, the stout acerate, and different forms 



of the tri- and quadriradiate spicules of the main ske- 

 leton, X 68. d' , the slender acerate (?) of the peristome 

 (the outer end imperfect), x 370. From type specimen 

 from Providence Reef. 



e. Erylus eylvMrigerus, part of the disk-spicule, in profile, x 190. 



e', the disk-spicule, from the front (tubercles omitted, 

 except at apex), x 190 ; ee", the same, the tubercles, x 300 ; 

 e'", the cylindrical spicule, two forms, x 68 : e"", the mi- 

 nute acerate spicule, young and adult, x 190 ; «'"", larger 

 stellate spicule, two forms, showing variation in the num- 

 ber and spination of the rays, x 190 ; «""", the small 

 stellate, x 370. From specimen from Providence Reef. 



/. Esperia gelatinosa, the subspinulate, /', large, and /", 

 small anohorate (the latter from the front and side), 

 /", bihamate spicules ; /"", trichite-bundle. x 370. From 

 specimen from Providence Island. 



g. Clathria decwmhens, the skeleton and echinating acuate 

 spicules, x 190. g', the equianchorate flesh-spicule, from 

 the front and side, x 370. From type specimen from 

 Etoilo Island; 



* Notc—Tho, figures in Ihis Plate hnya been prepared willi the aid of 

 sketches, to scale, made by Mr. Eidley. 



