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



4. Eucoronis angulata, n. sp. (PL 82, fig. 3). 



Frontal ring violin-shaped, twice as broad as high, on the upper and the lower margin concave, 

 with a deep sagittal constriction. Sagittal ring pentagonal, with straight horizontal basal rod, two- 

 thirds as high as the frontal ring. Eods of both rings with sharp prominent edges, bearing 

 numerous short pyramidal spines. 



Dimensions. Height of the frontal ring 0'09, breadth 017. 



Habitat. Central Pacific, Station 272, depth 2600 fathoms. 



Subgenus 2. Lithocoronis, Haeckel, 1881, Prodromus, p. 445. 

 Definition. Rings armed with numerous large, branched or arborescent spines. 



5. Eucoronis cervicornis, n. sp. 



Frontal ring kidney-shaped, in the upper half convex, in the lower concave, with sagittal con- 

 striction. Sagittal ring ovate, two-thirds as high as the frontal ring. Both rings armed with 

 numerous stout spines, irregularly branched like a deer's antler. (Very similar to Coronidiuni 

 cervicorne, PL 82, fig. 1, which I formerly confounded with it, but differing in the complete 

 sagittal ring, which in the latter form is incomplete and has lost its basal part.) 



Dimensions. Height of the frontal ring 012, breadth 0'2. 



Habitat. Central Pacific, Station 264, surface. 



6. Eucoronis arborescens, n. sp. 



Frontal ring kidney-shaped, with a deep sagittal constriction in the concave basal part. Sagittal 

 ring ovate, half as high as the frontal ring. Both rings armed with numerous thin, richly branched 

 and arborescent spines (branches much thinner and more numerous than in the preceding and 

 following species). 



Dimensions. Height of the frontal ring 015, breadth 0'25. 



Habitat. Equatorial Atlantic, Station 247, surface. 



7. Eucoronis challengeri, n. sp. (PL 82, fig. 4). 



Lithocoronis challengeri, Haeckel, 1881, Prodromus, p. 445. 



Frontal ring violin-shaped, one and a half times as broad as high, with a strong sagittal con- 

 striction. Sagittal ring nearly circular, two-thirds as high as the frontal ring. Both rings armed 

 with numerous irregularly branched spines. (The specimen figured, with red central capsule and 

 numerous xanthellse, was observed living by me at the Canary Islands.) 



Dimensions. Height of the frontal ring 01 to 012, breadth 014 to 017. 



Habitat. Cosmopolitan ; Atlantic, Indian, Pacific, surface and at various depths. 



