EURETE ERECTUM. 133 
The statements given above show that the sponges here described are very 
similar to Hurele erectum F. E. Schulze.’ Wilson has established three subspecies 
of this species: —tubuliferum,? mucronatum,® and gracile.’ One of these, H. e. 
mucronatum, differs from the sponges above described, and also from Schulze’s 
type, and from the other two of Wilson’s subspecies, by possessing oxyhexasters 
instead of discohexasters. This difference is in my opinion of such systematic 
importance that I consider it distinct from the other sponges placed in Eurete 
erectum. 
After the exclusion of this subspecies, Schulze’s EHurete erectum, Wilson’s 
FE. e. tubuliferwm, Wilson’s FE. e. gracile, and the sponges described above, remain 
as forms of one species. A comparison of these shows, that, although similar 
in the main, they differ from each other:in several minor points. The tubular 
body of the sponge is in Schulze’s type dichotomously branched, in the three 
others simple. This tube is in Wilson’s FH. e. tubuliferum and in my specimens 
14-17 mm. wide, in Schulze’s type and in Wilson’s FE. e. gracile 8-12 mm. The 
distal rays of the dermal pinules are in Wilson’s LH. e. gracile 50 u thick, in Schulze’s 
type and in Wilson’s E. e. tubuliferum only 35-40 u. In the specimens examined 
by me, dermal pinules occur together with distal rays as stout as those of EH. e. 
gracile and as slender as those of the other two. In my specimens the lateral 
and proximal rays of the gastral pentactine-like pinule-derivates are considerably 
larger than the corresponding rays of the gastral pinules proper. In the other 
three no such difference occurs, their gastral pinules and pinule-derivates being 
about as large as the gastral pinules of my specimens. The greatest differences 
between these sponges are met with in their scopules. To facilitate a comparison 
between the scopules of these sponges, short descriptions of them are tabulated 
on p. 134. 
In respect to their other characters, particularly the shape and size of the 
uncinates and discohexasters, the four groups of forms appear to agree quite 
closely. Schulze’s type was collected at Albatross Station 2819, near the Gala- 
pagos Islands, depth 717 m.; Wilson’s HL. e. tubuliferum at the Albatross 
Stations 3358 and 3359, off the south coast of western Panama, depth 875 and 
1015 m.; Wilson’s H. e. gracile at Albatross Station 3380, Gulf of Panama, 
depth 1693 m.; and the specimens examined by me at Albatross Station 4622, 
off the south coast of western Panama, depth 1067 m. The differences between 
1 F. EH. Schulze. Amerikanische Hexactinelliden, 1899, p. 72, taf. 17, figs. 1-3. 
2 H. V. Wilson. Mem. M.C. Z., 1904, 30, p. 63, pl. 7, figs. 9, 12; pl. 8, figs. 1-3, 6. 
3H. V. Wilson. Loc. cit., p. 68, pl. 8, fig. 7. 
4H. V. Wilson. Loc. cit., p. 69, pl. 8, figs. 4, 5, 8, 9, pl. 9, figs. 1, 3, 5. 
