dredged up from the Gulf of Manaar. 43 



Microciona quinqueradiata, n. sp. 

 (PI. IV. fig. 5, a-e.) 



Laminiform, extremely thin, hirsute, spreading. Cream- 

 colour. Spicules of four forms, viz. : — 1, long, setaceous, 

 curved, simple, acuate, 125 by 1-1 800th (PI. IV. fig. 5, a) ; 



2, short, thick, acuate, curved generally, with blunt end round 

 and a little less in diameter than the shaft, from which it is 

 differentiated by a slight constriction, 33 by 2-1800ths (fig. 5, 5) ; 



3, thin, slender, simple, acuate, 30-1800ths long (fig. 5, c) ; 



4, qradriradiate, consisting of four smooth pointed arms radi- 

 ating opposite each other from a common centre that is raised 

 so as to form a four-legged base to the fifth arm, which is 

 erect, longer than the rest, gradually pointed, thickly spined 

 throughout and the spines recurved, 6 by 5-1800ths 

 (fig. 5, d, e). Nos. 1-3 are erect, and the latter in greater 

 plurality than the others, while the long, spined arm of the 

 quadriradiate, which is very numerous, forms the echinating 

 part. Size variable; that of the specimen about \ inch in 

 horizontal diameter. 



Hab. Marine. On hard objects. 



Loc. Gulf of Manaar. 



Obs. This species is in growth, colour, and spiculation very 

 like the foregoing one ; but while the quadriradiate or echina- 

 ting spicule in M. quadrir -adnata is most like that of Dictyo- 

 cylindrus Vickersii {I.e.), it is the setaceous and thick, short, 

 acuate spicules respectively here which most resemble the 

 spiculation of that sponge. 



Microciona curvi&piculifera, n. sp. 

 (PI. IV. fig. 6, a-d.) 



Laminiform, extremely thin, hirsute, spreading. Cream- 

 colour. Spicules of three forms, viz. : — 1, long, setaceous, 

 smooth, acuate, curved chiefly towards the blunt end, which 

 is smooth and not differentiated from the shaft, 100 by 

 l-1800th (fig. 6, a) ; 2, the same, but much shorter, although 

 proportionately stouter, 15 by l-1800th (fig. 6, b) ; 3, cylin- 

 drical, bent in the centre, round at the extremities, smooth at 

 first, becoming when fully formed spiniferous throughout, 15 

 by §- 1800 th. (fig. 6, c, d). Nos. 1 and 2 are erect and fixed 

 in a layer of the bent spiniferous spicules, which project 

 outwards so that half of their length, lying parallel with the 

 other spicules, becomes the echinating part. Size variable ; 

 that of the specimen about \ inch in horizontal diameter. 



Hab. Marine. On hard objects. 



Loc. Gulf of Manaar. 



