REPORT ON THE TETRACTINELLIDA. 
87 
Genus 3. Spliinctrella, 0. Sclimidt. 
Spliindrella, O. Schmidt, Spong. Atlant. Gebiet., p. 65, 1870. 
Vulcanella, Sollas, Prelim. Account, Sci. Proc. Roy. Dubl. Soc., vol. v. p. 186, 1886. 
TlieneicTse in which the pores are generally dispersed, but the oscules few and highly 
specialised, each the large patent opening of a shallow cloaca, which is lined by a coarsely 
fenestrated membrane ; spicules as in Poecillastra. 
Sphinctrella cribrifera, Sollas. (PL X. figs. 13-20.) 
Vulcanella cribrifera, Sollas, Prelim. Account, Sci. Proc. Roy. Dubl. Soc., vol. v. p. 186, 1886. 
Sponge (PI. X. fig. 13a) more or less ovate ; lower half (PI. X. fig. 14a) embedded in 
a specimen of Caltliropella geodiides, Carter. Upper half bearing one or more large 
round oscules (PI. X. fig. 16), each surrounded by a marginal fringe of long oxeate 
spicules, the patent opening of a wide shallow cloaca, which is lined by a somewhat 
coarsely fenestrated membrane, covering the termination of the excurrent canals. Surface 
hispid. Canals with thick collenchymatous walls. Flagellated chambers 0'04 mm. in 
averag;e diameter. 
Spicides. — I, Megascleres. 1. Oxea (PI. X. fig. 17), stout, fusiform, straight or 
curved, not sharply pointed ; 3 ’035 by 0 '0671 mm. 
2. Oxea, long, slender, cylindrical, sharply pointed, straight or curved; 7 ’5 mm. and 
over, by O' 03 16 mm. 
3. Orthotrisene (PI. X. fig. 18), rhabdome straight, sharply pointed, with the cladi 
diverging chiefly outwards, scarcely at all forwards, usually bluntly pointed, or with the 
ends rounded. Ehabdome I'O by 0'0395 mm., cladi 0'25 by 0'0316 mm. 
4. Calthrops, isoactinate with conical pointed actines, each from 0'286 by 0'0395, to 
0'636 by 0'08 mm. 
5. Strongyle, straight or curved, terminating abruptly in rounded ends (sausage- 
shaped) ; 0'3.57 by 0'0276 mm. This form is confined to the margin of the cloaca. 
II. Microscleres. 6. Mieroxea, slender, fusiform, sharply pointed, straight or curved, 
of very various dimensions, from O'Oll mm. and upwards in length. 
7. Metaster (PI. X. fig. 20, the upper one of the two figures), very various in form, 
sometimes reduced to the plesiaster type ; spines often 0'0118 mm. long. 
8. Spiraster (PI. X. fig. 20, the lower one of the two figures), a slender spire of 
[ several turns, with slender spirally arranged spines ; 0'016to0'02 mm. in total length, a 
' single spine from 0'002 to 0'004 mm. long. 
' Colour. — Brown. 
I Habitat. — St. lago, Porto Praya, Cape Verde Islands, August 1873 ; depth, 100 to 
i 128 fathoms. 
