97(> THE VOYAGE OF H.M.S. CHALLENGER. 



2. Acanthodesmia ceratospyris^ n. sp. 



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

 striction, Sagittal ring semicircular, half as high as the frontal ring. The four gates between 

 the two rings are partly fenestrated by anastomosing branches of the numerous, irregularly branched 

 spines, wliich cover all three rings. Basal gate nearly circular, smaller than the sagittal ring. 



Dimensions. — Height of the frontal riug 0'08, breadth 0"12. 



Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 



3. Acanthodesmia corona, n. sp. (PL 93, fig. 5). 



Frontal ring kidney-shaped, nearly twice as broad as high, with a fiat sagittal constriction. 

 Sagittal ring semicircular. The four gates between the two rings are partly fenestrated by an 

 arachnoidal network, composed of thin, irregularly branched threads, arising from the rings. The edges 

 of aU three rings are armed with irregular thorns. Basal gate circular, larger than the sagittal ring. 



Dimensions. — Heisfht of the frontal rinir 0'08, breadth 0'14. 



Habitat. — Indian Ocean (Madagascar), Eabbe, surface. 



4. Acanthodesmia miilleri, n. sp. 



Frontal ring kidney-shaped, with a deep sagittal constriction. Sagittal riug ovate. The four 

 gates between the two rings irregularly fenestrated, with a few large polygonal meshes. Edges of 

 the rings with a few scattered thorns. Basal gate viohn-shaped. 



Dimensions. — Height of the frontal riug O'l, breadth 0'16. 



Habitat. — Tropical Atlantic, Station 347, surface. 



Subfamily 3. Eucoeonida, Haeckel, 1881, Prodromus, p. 445. 



Definition. — C o r o n i d a with six large gates (four lateral and tw^o basal gates). 



Skeleton composed of three rings perpendicular to one another, two of which are 



complete (the vertical sagittal, and the horizontal basal ring) ; the third is incomplete 

 (the vertical frontal riug). 



Genus 418. Eucoronis,^ Haeckel, 1881, Prodi'omus, p. 445. 



Definition. — C o r o n i d a with six large simple gates (four lateral and two basal). 

 Skeleton composed of two complete rings (the sagittal and basal) and one incomplete 

 (frontal) ring. Basal ring without typical feet 



' Eucoronis = Good cro\*Ti ; iv, y.o^mii. 



