R. KIRKPATRICK. 



There are also several isochelse arcuatse in which the alse and denticle are replaced 

 at one end by a spoon-like lamella. 



The presence in Myxilla of chelate bipocilla similar in many respects to those 

 found in the new species lophon spatulatus and /. flabeUo-digltatus is exceptional ; some- 

 what similar structures occur, however, in Myxilla iophonoides Svartzevsky (Mem. Soc. 

 Nat. Kieff, Tome XX., p. 340, PI. XV., fig. 27g-l) from the White Sea, but there are no 

 isochelse arcuatse. In other respects the spiculation of the new species is that of 

 a typical Myxillu. The isochelse arcuatse, though only half the length, resemble in 

 shape those of Myxtlla nobilis R. and D., from off the Rio de la Plata, and M. dl<jlt<it<i 

 R. and D., from the Cape of Good Hope. 



The specimen incrusting the rock was dredged from 254 fathoms, due wesb of 

 Balleuey Island ; and the specimen incrusting the Polyzoon from Winter Quarters, 

 No. 6 hole, 125 fathoms. 



LlSSODENDORYX SPONGIOSA. 



1887. Mij.rilla spongiosa R. & D. (15. p. 184, PI. XXVII., figs. 3-3f). 



1901. Lissodendoryx spongiosa, Topsent (29. p. 18). 



One small specimen and three minute fragments were obtained from three localities 

 in the neighbourhood of Winter Quarters. The complete specimen is cylindrical, 2 cm. 

 long, and 5 cm. in diameter, and is attached by part of its length to the branch of a 

 Polyzoon. The specimen is well preserved. The colour is white, an opaque white axis 

 showing through the transparent dermal layer. 



The spicular elements are similar to those of the Challenger type, and sigmata 

 occur in all, though in varying proportion. Topsent describes a variety of this 

 species from the ' Belgica ' collection, viz., L. spongiosa, var. asiginata, which is 

 wholly without sigmata. 



The specimens were dredged near Winter Quarters, (l) from near the ship, 20 fms. ; 

 (2) No. 12 hole, 25-30 fms. ; (3) McMurdo Bay, 4-10 fins. The species has been 

 found also off Rio de la Plata, GOO fms., Voy. 'Challenger.' The ' Belgica' collected 

 the var. asiginata in Lat. 71 14' S., Long. 89 14' W. in 450 metres. 



lOPHON RADIATUS. 



(Plate XXL, figs. 3, 4, 4a-c, and Plate XXV., fig. 4 a-c 1 .) 



1902. lophon radiatus, Topsent (29. p. 21, PI. III., fig. 13). 



Specimens and fragments come from five different localities. They are mostly in 

 the form of small cylinders about 4 mm. in diameter and varying in length up to 5 cm. 

 The longest (XXI. 4) is 5 cm. long and 4 mm. broad, tapering to a point at one end. 

 The colour is dark brown, a dark axial core of choanosome showing through the semi- 

 transparent dermal membrane. One specimen, the largest (XXI., fig. 3), has broadened 

 out into an oblong loose rather flabby mass, torn at each end, 4 cm. in length and 

 2' 5 cm. in breadth, and with a branch given off on each side near one of the ends. 



