220 SoittJiern Cross. 



dilate on it here. It is of some interest to note that Gray's 

 specimens were collected by Eoss in the " South Polar Seas." 



Distrihution. — Circumpolar. 



Stations. — Cape Adare : 20-24 fathoms : Jan. 2nd and 9th, 

 1900 (29° r.). 



Cape Adare : 2G fathoms : Nov. lOtli, 1899 (28' F.). 



Franklin IsLmd : 20-24 fathoms : Feb. 9tli, 1900 (29-8" F.). 



FXPLANATION OF PLATES. 



Platk XXVI. 

 Ophiosteira antarctiea. 



Fig. 1. — Tlie animal, natural size, from above. 



Fig. 2. — The disc, from above, magnified four times, showing the huge keel- 

 shaped plate between the radial shields. 



Fig. 3. — The same, showing an abnormal increase and diminution of the jilates 

 in two rays, x 4. 



Fig. 4. — The disc from below, magnified four times, showing the Oxihiura-Wke. 

 arrangements of the oval slseletou. 



Fig. 5. — The disc from the side (interradial view), x 4. 



Fig, 6. — An arm, near its base, from above, x 8. 



Kig. 7. — An arm, from the side, showing the gap between the ui>per arm- 

 plates, X 8. 



Fig. 8. — An arm, from below, showing the small under arm-plate, the large side 

 arm-plates meeting in the middle line below, and tlie short arm-spines, x 8. 



Figs. 9, 10, 11. — Views of the arm at some distance from the base, from above, 

 from the side and from below, all x 8. 



Plate XXVIL 



Five photographs of the disc of Ophionttira antarctiea to show tlie extraordinary 

 variations of the plates of the disc. 



Plate XXVIII. 

 OpMonotus victoriae. 



Fig. 1. — The creature from above, natural size. 



Fig. 2. — The disc, from below, x 2, showing the same Opldura-Vikii character of 

 the mouth as Opliivsteira. 



Fig. 3. — An arm, near the base, from above, x 4, showing the way in which the 

 side arm-plates encroach upon the upper arm-plates, and their mode of breaking u}). 



Fig. 4. — The same, from below, x 4, showing the encroachment of the side arm- 

 plates on the under arm-plates. 



Figs. 5, 6. — An arm near its end, from above and from below, x 4. 



