AR,EOSOMA OWSTONI. 193 



genitals and oculars each carry a small secondary, with one or two miliaries 

 in the central part of the proximal margin of the plate. The anal system is 

 covered with three or four irregular concentric rows of polygonal plates, a 

 few of the larger of which each carry a small secondary. 



In the small specimen, measuring 21 mm. in diameter (PI. 81, figs. 4, 5), 

 there are from the ambitus to the abactinal system 9 interambulacral and 15 

 ambulacral plates, in each column, while between the ambitus and the 

 actinal system there are 7 interambulacral and 12 ambulacral plates. 

 In the specimen measuring 52 mm. in diameter (PI. 81, figs. 1, 2) there 

 are 14 interambulacral and 23 ambulacral plates, from the ambitus 

 to the abactinal system. On the actinal side there are 11 interambu- 

 lacral and 14 ambulacral plates from the ambitus to the actinal system. 

 In a large specimen measuring 150 mm. in diameter, from the ambitus to 

 the actinal system there are 17 interambulacral and 27 ambulacral plates, 

 and between the ambitus and the abactinal system, 25 interambulacral and 

 47 ambulacral plates. The plates of the ambulacral areas are thus seen to 

 increase in number much more rapidly than the interambulacral plates. 



The specimens, which range from 20 to 150 mm. in diameter, were 

 taken by the " Albatross " at the following stations : 



Station 4875. Eastern channel, Korea Strait; 34° 19' N., 130° 9' E. 

 59 fathoms. Fne. gy. s., brk. sh. 



Station 4876. Eastern channel, Korea Strait ; 34° 20' N., 130° 10' E. 

 Bott. temp. 62.1°. 59 fathoms. Fne. gy. s., brk. sh. 



Station 4877. Eastern channel, Korea Strait; 34° 20' 30" N., 130° 

 11' E. 59 fathoms. Fne. gy. s., brk. sh. 



Station 4880. Eastern channel, Korea Strait; 34° 16' N., 130° 16' E. 

 59 fathoms. Fne. gy. s., brk. sh. 



Station 4946. Between Kagoshima and Kobe, Japan ; 31° 29' 10" N., 

 130° 34' 30" E. Bott. temp. 68.7°. 39 fathoms. Br. s., brk. sh., p. 



Station 5095. In Uraga Strait, Gulf of Tokyo, Japan ; 35° 5' 34" N., 

 139° 38' 36" E. Bott. temp. 57.8°. 58 fathoms. Fne. bl.,s., brk. sh. 



Bathymetrical range, 39-59 fathoms. Extremes of temperature, 68.7°- 

 57.8°. 



Eleven specimens. 



13 



