274 Mr. 11. Kirkpatrick on the MonaxonelUda 



same spicular elements, but o£ different dimensions, and has 

 the labis amono- its microscleres. 

 Locality. Off Balleney I., 254 £ath. 



HymerrhapMa rufa^ sp. n. 



The sponge forms a thin mud-coloured brown crust on a 

 branched Polyzoon. Tlie surface is smooth, and no pores or 

 oscules are visible. The consistence is rather tough. 



The skeleton of the choanosome is formed of longer and 

 shorter acanthostyles dressed vertically, that of the ectosome 

 being formed of tangentially arranged anisotornotes, either 

 isolated or in bundles. 



Spicules. — Megascleres : larger acanthostyles, 312 x 25 f*, 

 swollen at the head, spined all over, with larger curved spines 

 at the head. Smaller acanthostyles, 131 X 18*75 /n. Aniso- 

 tornotes of ectosome, 344 X 12 fi, straight, fusiform, attenu- 

 ating gradually at one end but abruptly at the other. 



Microscleres : isancoree, 28*5 /i long, with three or four 

 teeth at each end ; rarely the teeth are not developed, the 

 ends being in the form of hemispherical cups. 



Dredged near Winter Quarters, No. 10 hole, 130 fath. 



Ophlitaspongia nidificala^ sp. n. 



Sponge massive, of an inverted pyramidal shape, sessile, 

 narrow and contracted at the point of attachment. Surface 

 uniformly coarsely spinous. Circular oscules ('7 mm. in 

 diameter) on the upper surface, at the bases of the s])ines ; 

 (pores closed). Subdermal cavities flat and shallow. Flagel- 

 lated chambers diplodal. Colour dirty grey, the tips of the 

 spines being yellowish. Consistence hard and tougli. 



Slceleton consisting of dense branching axes of styles 

 cemented with spongin and echinated by smooth styles 

 passing at right angles from the axis to the surface. Ecto- 

 somal spicules in form of slender straight styles. Consider- 

 able tracts of dermal membrane were devoid of these spicules. 



Spicules. — Megascleres : large, straight, smooth styles, on 

 an average about 1000 x 50 fi. Also smooth curved kind, 

 625 /x long. Ectosomai styles straight, smooth, tapering 

 gradually to a pointy 406 x 9 yu,. 



Microscleres : toxa smooth, 638 /x long, 6*25 /a thick at the 

 centre. These spicules occur in nests or groups of five to 

 ten. 



This new species comes well within the genus Ophlita- 

 spomjia, Bk., as emended by Dendy. 0. seriata, Bk., O.sub- 

 hispida, Carter, and 0. meinbranacea, Thicle, all have toxa. 



