370 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



have 2 spines in a transverse series. The first plate has 3 or -i full- 

 sized spines. The surface of the plate external to the subanibiila- 

 crals is covered with granules uniform Avith those of the adjacent 

 actinal intermediate plates, obscuring completely the external suture 

 of the plates. 



Mouth plates small Avith a straight furrow margin bearing 10 fur- 

 row spines. Suboral spines 4 to 6 in about 2 series parallel to fur- 

 row. Outer part of plate with spaced granules, 8 to 10 in number. 



Madreporic body circular, flattish, medium-sized, with fine undu- 

 lating, branched, radiating striae ; its inner edge is about one-third r 

 from center. 



Color in life, abactinal surface scarlet, tips of arms pale buff; 

 spines pale ; actinal surface pale buff. 



No superambulacral plates; ampullae double; tube feet with 

 strong sucking disks. 



Type.—C2it. No. 32635, U.S.N.M. 



Type-locality. —Station 5617, off Ternate Island, west of Gillolo 

 Island, Molucca Islands, 131 fathoms, bottom not recorded ; 1 speci- 

 men. 



Distribution. — Known only from type-locality. 



Remarks. — This genus, like Narcissia and Ferdina, might reason- 

 ably be included in the Goniasteridae. It is placed in the Linckiidae 

 on account of the irregular abactinal skeleton, small marginals, and 

 the close granulation which covers the body and obscures the out- 

 lines of the actinal and abactinal plates, and on account of the gen- 

 eral appearance. 



The long, slender, furrow spines and prominent subambulacral 

 spines are unlike those of any other genus of Linckiidae, while the 

 abactinal and actinal intermediate spines are exceptional, and with- 

 out parallel in any of the Linckiidae having a large disk. 



Metrodira^ which I have placed provisionally in a special family, 

 has a smooth skin, much smaller disk, and an altogether different 

 adambulacral armature. That of Dissogenes is essentially goni- 

 asterid. 



The genus is not closely related to any other, and the fact that it 

 shows affinities to tAvo families has suggested the name, which sig- 

 nifies a two-fold descent. 



Genus FEKDINA Gray. 



Ferdina Gray, 1S40, p. 2S2. Type, F. flnrescens Gray. 



FERDINA GLYPTODISCA Fisher. 



Plate 56, fig. 5 ; plate 9.j, figs. 4, 4a-?> ; plate 104, fig. 2 ; plate 106, fig. 4. 

 Ferdina ghjptodisca Fishek, 1913c, p. 213. 

 DiagTiosis.— Resembling F. offreti Koehler; differing in having 

 all the prominent abactinal plates, and all the marginal plates with 



