450 PRISTEDT, SPONGES. 
The acuate spicules (Plate 25, fig. 20) are smooth, generally 
slightly curved, the greatest diameter being at the middle, 
tapering towards the base and the pointed end. These spicules 
are the most numerous in the sponge. The length is 0,35 mm. 
The linear acuate spicules (Plate 25, fig. 21) are not sö 
numerous as the preceding ones. They are always stram 
and very slender, the length varying from 0,2 to 0,25 mm. 
The inequianchorate spicules (Plate 25, fig. 22, 23) are of two 
sizes plainly distinct from each other. The larger spicules are 
disposed in rosettes as those of Esperia lingua Bow. (O. S.), the 
spicules in the rosettes being fewer in the variety. The length is 
0,08—0,1 mm. 'The smaller inequianchorate spicules are disposed 
without any order; the length of them is only 0.025—0,03 mm. 
The bihamate spicules (Plate 25, fig. 24) are C-curved, the 
straight length between the points 0,05 mm. 
Colour. "The colour is yellow. 
Habitat. Behring-islands, depth 5—10 fathoms (1078 V.I. 
Esperia helios n. sp. 
Plate 25, fig. 20—209. 
Only one specimen represents this species. This specimen 
is rounded and as large as a hazel-nut. The surface is hispid 
on account of projecting fascicules of spicules. Oscula minute, 
dispersed; the consistency is tolerably firm. 'The sponge is 
growing freely. 
The skeleton consists of acuate spicules, of inequi- 
anchorate and bihamate spicules. 
The acuate spicules (Plate 25, fig. 25) form the greater part of 
the skeleton; they are disposed without any order. They are 
sometimes subspinulate and often slightly curved. The length 
SK 055 mA 
The inequianchorate spicules (Plate 25, fig. 26, 27). These spi- 
cules are only of one kind, 0,08 mm in length. They are all 
congregated in rosettes as those of Esperia lingua Bow. (O. S.). 
