dredged up from the Gulf of Man aar. 41 



are characterized by the large, setaceous acuate, accompanied 

 by a thin one, together with a small clavate-spined spicule (the 

 echinating form), a smooth tricurvate and a naviculiform, 

 small, equianchorate (flesh-spicules), all arranged in tufts with 

 the flesh-spicules about their base ; but the tufts or " columns " 

 are much more developed in the former than in any other 

 species of the kind, whence it was called " Scopalina " by 

 Scjimidt in 1862. In M. armata the tufts are not so strongly 

 developed, but the tricurvate spicule is unusually so, and in 

 some instances so spread out as to resemble a long, thin, 

 straight acerate with a short abrupt curvature in the centre. 



Microciona affinis, n. sp. (PI. IV. fig. 15.) 



This species is very like the type species, Microciona atro- 

 sanguinea, in spiculation, but is extremely thin, has no tufts 

 (" columns "), and the colour now is whitish yellow. Its chief 

 specific difference, however, lies in the form of the equiancho- 

 rate, which being extremely abundant and thicker (but not 

 longer), from a greater projection of the central tongue-shaped 

 arm, presents the appearance of being barbed on the inner side 

 of the point, so that when viewed laterally this has much the 

 appearance of a fish-hook (PI. IV. fig. 15). 



Hah. Marine. On hard objects. 



Loc. Gulf of Manaar. 



Obs. This is one of the species to which I have above 

 alluded, in which the spiculation is essentially like that of the 

 type specimen of Dr. Bowerbank's genus Microciona, viz. M. 

 atrosanguinea, although it possesses no " columns." The 

 " fish-hook "-like appearance at the end of the central arm of 

 the equianchorate, when viewed laterally, may be owing to a 

 deficiency or hole in the upper part of the falcate septum which 

 ordinarily unites this arm to the shaft, and a corresponding 

 thickening of the septum at this part, which in some instances 

 appears to extend to the shaft itself; but the object is too 

 small for me to state, with any certainty, more than that it 

 presents the " fish-hook appearance " mentioned. 



Microciona bulboretorta, n. sp. (PI. IV. fig. 3, a-e.) 

 Laminiform, extremely thin, hirsute, spreading. Colour, 

 when dry, whitish yellow. Spicules of four forms, viz. : — 1, 

 long, setaceous, smooth, acuate, with inflated blunt end turned 

 to one side, 175 by2-1800ths (PL IV. fig. 3, a) ; 2, the same, 

 but short, and spined halfway up from the blunt end, 30 by 

 1^-1 800th (fig. 3, b) j 3, the same, about half the length of 

 the last (fig. 3, d, e) ; 4, thin, smooth, acuate, 40-1800ths long 

 (fig. 3,c). All the spiculation is erect, and no. 4 in tufts 



