BY E. F. KALLMANN. 651 



the surface, including tliat of the processes, is covered witli small, 

 usually blunt conuli. The largest specimen measures 95 mm. in 

 length, 80 nun. in breadth, and 70 mm. in height; and the pro- 

 cesses, which are generally slightly flattened and somewhat ap- 

 pressed to the surface, avei-age about 4 mm. in diameter at the 

 base, and vary in length up to about 10 mm. The dermal mem- 

 brane is strongly developed and fairly easily separable, and 

 usually presents to the naked eye a minutely reticulate pattern 

 due to the mode of arrangement of the dermal pores (PI. xxxviii., 

 fig. 5). Internally, the sponge is traversed vertically by rather 

 numerous main efferent canals, measuring up to 3 mm. in diameter, 

 which open into small, usually inconspicuous oscula situated on 

 the upper parts of the surface. The oscula occur on and between 

 the digitiform processes indifferently. The consistency in alcohol 

 is soft and compressible, and lacking in toughness; the texture, 

 however, is compact. The colour in life is some shade of brown, 

 — usually a darkish or slaty-brown, sometimes with a greenish 

 tinge; in alcohol, it is brownish-grey on the surface and pale 

 grey within. 



The dermal reticulation (PL xxxviii., fig. 5) is formed of more 

 ar less polygonal meshes of various size up to about 300 by 200/x, 

 usually longer than broad, but varying in actual shape, in different 

 parts of the surface, from subcircular to nearly oblong, and 

 separated by usually narrow boundaries from 35 to (rarel}') 

 150/A in width. Within each of the meshes, the dermal mem- 

 brane is perforated by numerous pores. In consequence, no 

 doubt, of their having become closed through conti'action, the 

 pores sometimes are apparently absent; and in one of the speci- 

 mens examined, presumably owing to excessive contraction, even 

 the dermal reticulation was indistinguishable. No megascleres 

 are present in the dermal membi'ane, and only veiy few scattered 

 trichites; but in the boundaries of the meshes of the reticulation, 

 spined microxea occur more numerously than elsewhere in the 

 sponge. 



Skeleton. — When a piece of the sponge is treated with caustic 

 potash, it usually decomposes entirely, yielding nothing but a 



