666 REVISION OF THK AXINE|:iLIDiE, iii., 



2'5 mm., and exhibiting an indistinct arrangement in longi- 

 tudinal rows; but in the case of the spirit-specimen, except 

 where the dermal membrane has been destroyed, it is scarcely 

 more then minutely pustulose. On complete removal of the 

 sarcode by maceration, the skeleton-sponge is found to be com- 

 posed, just as in the case of var. massalis, of conjoined, parallel, 

 thin lamellse perpendicular in direction to the plane of tlie 

 sponge; and it is to a serration of the edges of these lamellse 

 that the surface-prominences are due. The only oscula observed 

 svere marginally situated and of very small size, the largest not 

 exceeding 05 mm. in diameter. The dermal membrane is well- 

 developed and very distinct, and is underlain (between the 

 surface-prominences) by extensive subdermal spaces; owing to 

 its imperfect preservation in the present specimens, dermal 

 pores were not observable. The unmacerated dried sponge is 

 somewhat hard and with difficulty compressible, brittle rather 

 than elastic, and pale greyish or almost whitish in colour. In 

 alcohol, the consistency is dense and firm, moderately flexible, 

 compressible and resilient; and the colour is yellowish pale grey. 



The structure of tlie "skeleton-sponge" is essentially the same 

 as in the case of var. massalis; but the lamellse are much thinner 

 (only about 05 mm. in thickness), more closely approximated 

 (at most 1*75 mm. apart), and, in proportion to their width (i.e., 

 in proportion to the thickness of the sponge-lamina), more com- 

 pletely united with one another. In the present variety, ac- 

 cordingly, the structure is notably denser, and the texture also 

 is much more coarse. 



Skeleton.— In each lamella the skeleton consists, again as in 

 the case of var. massalis, of a dense and intricate reticulation of 

 paucispicular main and connecting fibres, and numerous con- 

 necting spicules; but the fibres are here less clearly defined, the 

 skeleton-pattern accordingly is somewhat more irregular, the 

 megascleres are larger, and there is a relatively great scarcity of 

 slenderer megascleres occurring interstitially and dermally. In 

 other respects, apart from diiferences depending upon the greater 

 thinness of the lamella? and the much lesser width of the inter- 

 lamellar in the present case, the skeletal characters of the two 



