THE OPHIUEIDiE. 



141 



adradial edge straight, abradial edge curved; and outer edge straight; they 

 are separated by a single row of scales ; mostly there are no scales along 

 their outer edge. Under side of the disk covered with scales similar to 

 those on the dorsal side. Edge of the disk rather sharp. 



Three rather stout, smooth arm-spines, the middle one the stoutest; they 

 are as long as one joint and a half. One large oval tentacle scale. 



Color in alcohol : pale brown. 



Stations 3380, 899 £, 6 specimens ; 3406, 551 f., 1 specimen. 



Inside the large mouth papilla there is sometimes seen another papilla, 

 and it thus looks as if there were two mouth papilla; on each side ; however, 

 it is not so : this papilla belongs to the first mouth tentacle, and is thus 

 the same as that usually seen in Amphiura, Some of the specimens have 

 one half of the disk regenerated and the three arms more or less shorter 

 than the rest. This species thus has self-division. 



Evidently this species is closely related to OjMactis flexuosa Lym., from 

 which it is separated only by small differences : the form of the mouth 

 shield, of the large mouth papilla (?), of the ventral plates, and of the radial 



/ 



ofundi 



ofundi 



them. Finally, 0. flcxiwsa has 

 The latter character evidently 



five arms, whereas 0. f 



is the most important. 



says : " The ten specimens from Station 142, 150 fathoms, may be the young 



On page 116 of the Challenger Report, Lyman 



/ 



/ 



has but five." 



ofundi is not the young of O.fl^ 



/ 



described by Lyma>s^ only 7 mm. Upon the whole, we think there is no 

 sufficient evidence that in any species the young has six arms, the adult only 

 five. We therefore also doubt that Lyman is right in asserting that to be 



0. Mullen Ltk. We have found nothing in the literature which 



so m 



definitely shows that to be the case. Lutken (Additamenta, Vol. XL 

 p. 230) describes an older 5-armed specimen, and then only says : " Though 

 I presume this form to be a separate species, I will not omit pointing out 



Miiller 



L JUNG- 



MAN* says, by the description of the var, qmnqzieradia, that he has not 

 been able to tell definitely whether it was a new species or the adidt 

 of 0. Mullen, ' Lyman himself says (111. Catal. Mus. Comp. Zool., Vol. I. 



* Ofvers, l^l Svcnska Veteiisk. Akad. rorliandl, 1871- 



«r 



7 



