472 " THETIS " SCIENTIFIC RESULTS. 



ESPERIOPSIS FERRUGINEA, sp. nov. 



(Plate xlv., tig. 26.) 



Station 48. 



Sponge consisting of a series of angular coalescent branches, 

 about 5mm. in diameter, forming a clathrate mass with an open 

 subhoneycombed surface. Texture tender, brittle and inelastic. 

 Colour like rusty iron, with the tips of the minute conuli white 

 or grey. The conulose ridges are low, irregular, and enclose a 

 series of variously shaped lacunae from 0-5 to 1-5 mm. or more in 

 diameter, the edges of which are fringed with a few small conuli. 



The main fibres consist of bundles of loosely arranged spicules 

 about 0"l5mm. in diameter. The secondaries and connecting 

 fibres are very indefinite, embracing a few ill arranged whispy 

 lines of spicules, disposed in multi- oi unispicular I'ows; the mesh 

 is coincident with the length of the spicules, and is more or less 

 rectangular, but somewhat obscured by the numbers of scattered 

 spicules in the choanosome. 



Megascleres: — straight styli or subtylostyli of various sizes from 

 0*2 to 0-35mm. in length and from 0-008 to 0015 ram. in diameter. 



Microscleres : — rather stout isochelae with a curved shaft and 

 three well developed teeth on each end ; length about 0-03 mm. 



PSEUDOHALICHONDRIA, Carter. 



PSEUDOHALICHONDRIA FIBROSA, Whitelegge. 



P&eiidohalichojidria fibrosa, Whitelegge, Rec. Austr. Mus., iv., 

 pt. 2, 1901, pp. 78 and 117, pi. x., fig. 8. 



Station 53. 



A fine specimen of this species was obtained off Crookhaven 

 River in 23 fathoms The example measures nearly 300 mm. in 

 height and has live main branches, all of which are more or less 

 coalescent ; the stem is 80 mm. long and 10 mm. in diameter. 

 The branches are flattened — in the plane of branching — and each 

 presents one or more well marked longitudinal grooves ; on the 

 lateral branches the grooves are continued from the base of the 

 peduncle to the much compressed and somewhat dilated apices. 



Epidermal surface glossy, with conical projections about one 

 or two mm. apart. The grooved areas are depressed, and have 

 microscopic transverse corrugations— these are probably due to 

 the contractile nature of the dermal membrane — overlaying the 

 well defined grooves. Pores, if present, are so contracted as to be 



