286 DISCOVERY REPORTS 



Isodictya cactoides (Kirkpatrick). 



Desmacidon kergiiekiisis, var. cactoides, Kirkpatrick, 1908, p. 38, pi. xix, fig. 2, pi. xxiii, fig. 2; 

 Isodictya cactoides. Burton, 1929, p. 424. 



Occurrence. St. 39: South Georgia, 179-235 m.; St. 123: South Georgia, 230-25001.; St. 190: 

 Palmer Archipelago, 93-130 m.; St. MS 68: South Georgia, 220-247 m. 



Distribution. Victoria Land. 



Isodictya microchela (Topsent) (Plate LI, fig. 5). 

 Homoeodictya microchela, Topsent, 191 5, p. 37. 

 Occurretice. St. WS 86: Falkland Islands, 151-147 m. 



Remarks. The original description of this species is unaccompanied by any illustra- 

 tion, so that it can only be identified with hesitation. The present specimen appears to 

 belong to it, but if the identification is correct then the external form of this species 

 is that shown in Plate LI, fig. 5. 



Distribution. Burdwood Bank. 



Isodictya erinacea (Topsent). 



Homoeodictya erinacea, Topsent, 191 6, p. 169; //. kirkpatricki, id., loc. cit., p. 169; //. erinacea, 

 id., 1917, p. 68, pi. iii, fig. i, pi. vi, fig. 15 ; //. kirkpatricki, id., loc. cit., p. 70, pi. i, fig. 2, pi. vi, 

 fig. 14; Desmacidon doryphora, Brondsted, 1926, p. 2, figs, i, 2. 



Occurrence. St. 190: Palmer Archipelago, 93-130 m. 



Remarks. In view of the strong likeness in other respects, I cannot accept the 

 separation of Homoeodictya kirkpatricki and Desmacidon doryphora merely on account 

 of the difference in the sizes of their respective megascleres, for that is the only 

 character in which they diff'er. Under Isodictya setifer (see above), I have shown how 

 much the dimensions of the spicules may vary within a single species of Isodictya, and 

 the evidence from this source alone is sufficient to justify the identification of Br^nd- 

 sted's species with that of Topsent. With regard to Homoeodictya erinacea, there is so 

 much resemblance to the two other species that it is not possible to regard the mere 

 presence of raphides or of tiny bosses on the chelae as characters necessitating a specific 

 distinction. 



Distribution. Graham Land; Victoria Land. 



Isodictya toxophila, sp.n. (Plate LIT, figs. 2, 3; Plate LIII, figs, i, 2; Fig. 18). 



Holotype. B.M. 28. 2. 15. 158. 



Occurrence. St. 39: South Georgia, 179-235 m.; St. 148: South Georgia, 132-148 m.; St. 175: 

 South Shedands, 200 m.; St. 190: Palmer Archipelago, 93-130 m.; St. WS 27: South Georgia, 

 106-109 m. 



