492 On the ^Challenger ' Monaxonida. 



dermal crust. Typically corticate; beset with mammiform 

 projections, some of wliich bear oscula and others pores. 



Latrunculia ajncalis^ n. sp. 



Sponge hemispherical. Osculura-bearing and pore-bearing 

 processes distinct : the former at the top of the sponge, in 

 form conical ; the latter smaller, more abundant, abruptly trun- 

 cated. Yellowish grey. Corticate. Fairly compact, but 

 spongy internally. Skeleton : the sceptrella3 form a con- 

 tinuous dermal crust, below which the skeleton is loose and 

 irregular, denser towards the surface. Spicules: — (1) smooth 

 acuates, size "6 by '014 millim. ; (2) sceptrellee, with expanded 

 spinose base^ straight shaft, and four or five discoid whorls 

 with indented margins, the lowest whorl the largest ; shaft 

 produced upwards into a long, smooth, terminal portion ; 

 length of spicule "126 millim., diameter of largest whorl •044 

 millim. 



Localities. Off Christmas Harbour, Kerguelen, 70 fath. ; 

 Station 320, off the Eio de la Plata, 600 fath. 



Latrunculia hrevis^ n. sp. 



Much resembling in appearance and skeleton-arrangement 

 L. oj)icalis, but the corticate skeleton of acuates is barely re- 

 presented. Spicules: — (1) smooth acuates, size '6 by '0126 

 millim. ; (2) sceptrellte, differing from those of L. apicalis in 

 having no apical prolongation. The upper whorls are approxi- 

 mated so as to form a thick bush at the top ; length '05 

 millim., diameter of largest whorl '044 millim. 



Locality. Station 320, off the E.io de la Plata, 600 fath. 



Latrunculia Bocagei^ n. sp. 



Subglobular, sessile ; resembling L. ajncalis in appearance 

 and skeleton-arrangement. Corticate. Spicules : — (1) 

 smooth acuates, size "6 by '018 millim. ; (2) sceptrellaj, with 

 slightly expanded base, armed with two whorls of spines, and 

 a smooth, stout shaft, bearing three distinct, subequal, separate 

 whorls towards the apex, and ending in a tuft of spines which 

 follows close upon the last whorl. Each disk-like whorl is 

 deeply but unequally notched all round ; length '07 millim., 

 diameter of whorls '03 millim. 



Locality. Kerguelen, 10-70 fath. 



Latrunculia (?) acerata^ n. sp. 

 Massive, cake-like ; without mammiform projections. 



