68 CALYCOSILVA CANTHARELLUS. 



simplex, var. nov. 



Plate 1, figs. 9-19, 25-29; Plate 2, figs. 1, 2, 4-6, 14, 16; Plate 3, fig.'^. 6, 7; Plate 4, figs. 21, 22; Plate 

 5, figs. 3, 6, 10, 16, 17; Plate 6, figs. 1-4, 22, 23; Plate 7, figs. 11, 15, 18. 



megonychia, var. nov. 

 Plate 4, figs. 1-20; Plate 5, fig. 21; Plate 7, fig. 19. 



All the specimens of this species were trawled at Station 4651 off northern 

 Peru, on 11 November, 1904; 5°41.7' S., 82°59.7' W.; depth 4063 m. (2222 f.); 

 they grew on sticky, fine, gray mud; the bottom-temperature was 35.4°. 



The complete specimen shows that the sponge is, in outer appearance, similar 

 to the mushrooms of the genus Cantharellus, and to this the specific name refers. 

 It possesses spirally twisted onychhexasters, which I name helonychhexasters. 

 Such spicules have not been found in any of the other (more or less fragmentary) 

 specirnens. In some of the latter the average and the maximum size of the 

 onychhexasters is considerably greater than in the others. On account of this 

 and other differences between them I distinguish three varieties within this 

 species : — var. helix, with helonychhexasters (the complete specimen) ; var. 

 megonychia, without helonychhexasters, with larger onychhexasters (six frag- 

 mentary specimens) ; and var. simplex, without helonychhexasters, with smaller 

 onychhexasters (twenty-five more or less fragmentary specimens). Twenty- 

 four of the specimens of var. simplex are identical and obviously parts of the 

 body proper of the sponge. These are designated C. c. var. simplex (A). One 

 corresponds to the basal part and the stalk of the complete specimen. This is 

 designated C. c. var. simplex (B). 



Shape and size. The complete specimen of C. c. var. helix (Plate 6, fig. 18) 

 appears as a horizontally expanded plate, from near the centre of the lower side 

 of which a slender stalk arises. The stalk is 52 mm. long, nearly circular in 

 transverse section, and at the lower end, where it was attached to the sea-bottom, 

 4 mm. thick. It gradually thickens above and measures at its upper end, where 

 it gradually passes into the body proper of the sponge, 7 mm. in transverse diame- 

 ter. Its lower portion is inarkedly bent and has the appearance of having first 

 grown somewhat obliquely and later vertically. The plate, which is to be con- 

 sidered as the body proper of the sponge, is irregularly oval in outline and 

 measures 68 by 92 mm. Its central part, to which the stalk is attached, is 6 mm. 

 thick. Towards the margin it thins out. The plate is somewhat bent in an 

 undulating manner and at one place strongly curved inwards. In the figure 



