944 THE VOYAGE OF H.M.S. CHALLENGER. 



2. Lithocircus quadricornis, n. sp. (PI. 81, fig. 9). 



Gate square. Eing square, with three sharp denticulate edges, and four large buuehes of 

 richly branched spines on the four corners. In each corner arise three curved spines, about as 

 long as the diameter of the ring ; their numerous irregular branches are forked and curved like 

 the antlers of deer. 



Dimensions. — Diameter of the gate 0'07 ; length of the horns 0-06 to 0'09. 



Habitat. — South Pacific, Station 300, depth 1375 fathoms. 



3. Lithocircus decimalis, n. sp. (PI. 81, fig. 15). 



Gate elliptical. Eing pentagonal, with three prominent edges and five pairs of branched spines 

 on the five corners. In each corner arise two or three curved spines, about as long as the radius 

 of the gate, each with two to four forked branches. 



Dimensions. — Diameter of the gate 0'08 ; length of the spines 0'03 to 0"05. 



Habitat. — North Atlantic, Station 354, surface. 



4. Lithocircus hexahlastus, n. sp. (PL 81, fig. 17). 



Gate elliptical. Eing hexagonal, with three prominent edges and six pairs of branched spines, 

 arising from the six corners. Each of the twelve spines is short and stout, only half as long as 

 the radius of the gate, and bears a bunch of ten to twenty short, densely aggregated, conical 

 or horn-like curved branches. 



Dimensions. — Diameter of the gate O'l ; length of the spines 0'02 to 0'03. 



Habitat.— Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 



5. Lithocircus crambessa, n. sp. (PL 81, fig. 6). 



Gate elliptical or subcircular. Eing hexagonal, with three wing-shaped distorted edges and six 

 groups of branched spines, arising from the six corners. In each corner arise three short and stout 

 divergent spines, each bearing a bunch of numerous short roundish branches like a cauliflower, 

 scarcely as long as the thickness of the ring. 



Dimensions. — Diameter of the ring 01 to 0'12, length of the spines O'Ol to 0'02. 



Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 



6. Lithocircus tarandus, n. sp. (PL 92, fig. 19). 



Gate circular. Eing hexagonal, with three sharp edges and six pairs of large branched spines, 

 arising from the flat lateral edges on the six corners. Each of the twelve spines is horizontally 

 expanded, longer than the diameter of the ring and dichtomously forked like the antlers of a rein- 



