180 Mr. H. J. Carter on the 



less in diameter than the shaft ; the shaft fusiform, and the in- 

 flation elliptical, mostly elongate and terminal. Flesh-spicules 

 of two or three forms, viz. : — 1, inequianchorate of different 

 shapes ; 2, simple bihamate ; 3, simple tricurvate or bow-like. 

 Forms massive, lobular, for the most part incrusting and amor- 

 phous ; sessile or stipitate, and fixed by stem-like enlargement 

 of the spiculo-fibre. 



Group 9. Hymedesmina. 



Sarcode pale yellowish. Skeleton composed of reticulate 

 spiculo-fibre whose interstices are filled up by areolar sarcode, 

 which when dry resembles crumb of bread. Surface substelli- 

 form, heterahedrally reticulate, like that of Esperia. Colour 



pale yellowish white. Vents and pores ? Texture crumb- 



of-bread-like, delicate, crushable. Spicules of two kinds, viz. 

 skeleton- and flesh-spicules. Skeleton-spicule simple acerate, 

 subacuate fusiform, also like that of Esperia, or simple acuate, 

 according to the species. Flesh-spicules anchorate, tricurvate, 

 and bihamate, according with the species ; the anchorate pecu- 

 liar, consisting of a straight shaft trenchant and notched circu- 

 larlyin the centre and at each end on the inner aspect, terminated 

 respectively by a single arm recurved, also trenchant on the 

 inner border, pointed and turned to one side at each end in oppo- 

 site directions. Forms incrusting, massive, lobed, amorphous. 



Family 2. Suberitida. 

 Group 10. Cavernosa. 



Pale tawny yellow or purple. Skeleton cavernous, multi- 

 locular ; walls of the cavities consisting of a felt-like accumu- 

 lation of the spicule of the species ; cavities filled with the 

 same kind of material, but loose, open, areolar, and more 

 sarcodic than spiculous. Surface even, undulating, or nodular. 

 Dermal layer compact. Vents and pores situated in areolated 

 papillae, which are single and separate, or arranged in patches 

 or groups united hexagonally ; or with the vents simply grouped 

 together over the nodular eminences, and the pores generally 

 diffused throughout the intervals in the interstices of the 

 dermal reticulation. Texture essentially cork-like. Spicule 

 of one kind only, viz. that of the skeleton, and of one form 

 only, viz. pin-like ; shaft smooth, curved, fusiform, more or 

 less taperingly pointed ; head as large or larger in diameter 

 than the thickest part of the shaft, subterminal and elliptical, 

 or terminal and bulb-like, subspherical and subterminal, or 

 almost spherical and terminal. Free or floating forms massive, 

 water worn, more or less rounded: fixed forms spreading hori- 



