114 BULLETIN OF THE 



Ophiomusium Liitkeni sp. nov. 



Plate V. Figs. 138-140. 



Special Marks. — Disk covered by large, angular, smooth, swollen plates, of 

 which the interbrachial marginal is largest. Arms wide and thick, with side 

 arm-plates much swollen and rounded, and bearing a spine on their upper 

 surface. 



Description of an Individual (Station 192). — Diameter of disk 13 mm. 

 Length of arm about 45 mm. Width of arm close to disk, without spines, 

 2.5 mm. Four or five large square mouth-papilla) on each side, with one, 

 small and slender, at apex of jaw, all closely joined, those without being deeper 

 than those within. Mouth-shields rudely three-sided, having a blunt angle 

 within and a curved outer edge broken by angles. Length to breadth 2.5 : 2.7. 

 Side mouth-shields longer than broad, and thick, meeting well within, where 

 they are slightly narrower than without. First under arm-plate small, nearly 

 square, with all four angles rounded ; the next two larger, pentagonal, with an 

 angle inward, outer lateral corners rounded, and deep re-entering curves on 

 the lateral sides, where the tentacle-scales stand ; the under ann-plates beyond 

 these are minute and triangular, having an angle inward and the outer edge 

 slightly curved. Side arm-plates large, swelling without into a rounded ridge 

 and forming the greater 2)art of the covering of the arm. Upper arm-plates 

 triangular, with an angle inward, and all three sides slightly curved. Disk 

 massive and flat, covered with thick, slightly swollen plates, one pentagonal 

 primary in the centre, surrounded by five rudely hexagonal plates ; interbra- 

 chial spaces filled by one hexagonal plate within, and a smaller quadrangular 

 extending to the very large marginal plate, which is much swollen and has a 

 constriction on the outer edge. Radial shields large and angular, wider with- 

 out than within, with outer angles rounded, separated their entire length within 

 by an hour-glass-shaped wedge of three small plates. Lower interbrachial 

 space covered by the great marginal plate, the broad genital scales extending 

 from the mouth-shield to the marginal plate, and by three intermediate plates. 

 There are two short blunt arm-spines, besides a supplementary spine on the 

 top of the side arm-plate. Tentacle-pores at the second and third under arm- 

 plates only, with one small round scale on each pore. Color in alcohol, 

 grayisli. 



By its general shape, and by the extra spines on top of the arm, this species 

 approaches 0. acufcrum, but is distinguished by form and arrangement of 

 disk-plates. 



Station 192, 129 fathoms, 3 specimens. 



Ophiomusium validum I..1N. 



Ophiomusium validum. Dn. (loics, Vifstiiidisk. (.)\i\\. Of. Kong. Akad. p. 018. 1871. 



riatcI.FlKfl. 7-0. 

 Special Marks. — Most of the lower interbrachial space outside the mouth- 

 shield 1.1 occupied by broad genital scales and a great central plate. No under 



