AMPHIURIDAE 



291 



They are slender, pointed, except the second from below from a few joints outside the 

 disk ; this spine is broader than the others and terminates in two small hyaline hooks, 

 the spine thus having the shape of a small hatchet. (The species name refers to this 

 character.) No tentacle scale. The specimens (dried) show no trace of particular colour. 

 This very characteristic species does not seem nearly related to any other known 

 species of the genus Amphiodia (or Amphmra— to which latter genus it might perhaps 

 equally well be referred, just as well as Amphmra Eiigeniae). 



Fig. 24. Amphiodia ascia, n.sp. Part of oral side {a) and dorsal side {b). Arm joints from 



the middle of arm, oral side (c). X20. 



Ophionephthys magellanica, n.sp. 



St. WS 742. 5. ix. 31. 38° 22' S, 73° 41' W, 35 m. 6 specimens. 



These specimens having all lost the disk, no complete description of the species can 

 be given. However, the shape of the mouthparts and the arm plates shows it to be 

 decidedly different from any other species of Ophionephthys hitherto described, and since 

 the genus Ophionephthys was not hitherto known to occur in the Magellanic region, 

 I have deemed it desirable to name the species, in spite of the incompleteness of the 

 description. 



The arms are very long and slender, as usual in this genus; as they are all broken, 

 nothing can be said of their actual length. 



There are three rather small, scale-like, outer mouth papillae, much smaller than the 

 infradental papillae. The buccal shields are spade-shaped, with a more or less con- 

 spicuous outer lobe; the adoral shields, which join within, have a rather sharp 

 outer (adradial) angle. The hole in the jaws, characteristic of Ophionephthys, as well as 

 of Ophionemo, is sometimes indistinct (Fig. 25 a). Ventral arm plates usually distinctly 

 longer than wide, with distal edge slightly concave. Dorsal arm plates fan-shaped, 



