TETKAXONIDA. 23 



Sub-Order Halichondrina, Vosmaer. 

 Family Axinellid.e, Ridley and Dendy. 



AxiNELLA SUPRATUMESCENS. 



(Plate XXII., fig. 8, aud Plate XXVI., figs. Ga-b.) 

 1907. Axinella supratumescens Topsent (31. p. (i). 



The specimen, which is a small conico-cylindrical fragment 3'5 cm. long and 9 mm. 

 in diameter, is the hroken-off end of a branch. The surface is finely hispid, aud the 

 broken cud shows the dense but flexible central axis. 



The straight or slightly curved styles are mainly of two sizes, the larger (XXVI. 

 6a) being 594 x 12 '5 ju, and the smaller (XXVI. 6b), which forms the surface tufts, 

 306 X 6-25/i. 



The specimen was dredged near Winter Quarters in 10 fms. 



The ' Fran^ais ' Antarctic Expedition obtained numerous specimens from Booth- 

 Wandel Island and Wiencke Island, from low water up to 30 metres (Topsent, 31. p. 74). 



SiGMAXiNYSSA Kirkpatrick. 



1907. Sigmaxinyssa K\rk^s.ix\dk. (10a. p. 272). 



Cup-shaped Axinellidse with longitudinal skeletal fibres joined l)y transverse ones 

 on the inner aspect, and with tufts given off at right angles to these on the outer 

 aspect. Megascleres, oxeas ; microscleres, sigmata and toxa. 



SiGMAXiNYSSA PHAKELLIOIDES. 



(Plate XVII., fig. 6, and Plate XXIV., figs. 4a-c.) 

 ]907. Sigmaxinyssa phakellioides Kirkpatrick (10a. p. 272). 



Sponge sessile, cornucopia- or cup-shaped. Inner surface smooth, outer surface 

 coarsely pilose. Consistence rather hard, but flexible. Colour in spirit, grayish drab. 

 Inner surface with numerous small oscules, each about 1 mm. in diameter ; outer 

 surface pilose, with dermal membrane perforated by round pores 95 /x in diameter. 



Skeleton. On inner surface formed of close set longitudinal lines joined by 

 cross bars, and giving off tufts of fil)res, which proceed outwards at right angles to the 

 outer surface, pushing up the dermal membrane, but barely projecting beyond it. 



Spicules. Oxeas, 835*5 x 42-25 fi, curved at centre, sharp-pointed. Sigmata, 

 81-25/x long, 35-75 fi l)road, aud 3-25;u thick, often with an angular bend at centre 

 of shaft. Toxa, 130 /x long, and 3 • 25 /x thick at centre, with smooth surface. 



This species bears in its outward aspect a very close resemblance to cup-shaped 

 species oiPhakellla; also the skeletal arrangement is like that of Phakellia ; the oxeas, 

 sigmata and toxa are those of a typical Gellius. The Axinellid genus Sigmaxinella 

 Dendy, which has microscleres in the form of sigmata, has styles for megascleres. 



The only specimen was dredged off Coulman Island iu 100 fms. 



VOL. IV. ^ P 



