TETRAXONIDA. 23 



SUB-ORDER HALICHONDRINA, Vosmacr. 

 FAMILY AXTNELLID.E, Ridley and Dendy. 



AxiNELLA SUPRATUMESCENS. 



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

 1907. Annelln supratumescens Topsent (31. p. G). 



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

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

 broken end 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/x, and the smaller (XXVI. Gb), which forms the surface tufts, 

 30G x 6'25/u. 



The specimen was dredged near Winter Quarters in 10 frns. 



The ' Frangais ' Antarctic Expedition obtained numerous specimens from Booth- 

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



SIGMAXINYSSA Kirkpatrick. 

 1907. Sigmaxinyssa Kirkpatrick (10a. p. 272). 



Cup-shaped Axinellidae with longitudinal skeletal fibres joined by transverse ones 

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

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



SIGMAXINYSSA PHAKELLIOIDES. 

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

 ]!)07. Sifjmaxinyssa phaMlioidcs 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 p. in diameter. 



Skeleton. On inner surface formed of close set longitudinal liui's joined by 

 cross bars, and giving off tufts of fibres, 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 fj. long, 35' 75 /j, broad, and 3' 25 fj. thick, often with an angular bend at centre 

 of shaft. Toxa, 130 n long, and 3'25/x thick at cent re, with smooth surface. 



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

 species of J'/uiki ll'm also the skeletal arrangement is like that of Phukcttiii ; I he oxeas, 

 sigmata and toxa are those of a typical Gellius. The Axinellid genus Si<ini<ij'in<ll<t 

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



The only specimen was dredged oil' Coalman Island in 100 fins. 



VOL. IV. 2 D 



