54 



I. EJIMA. 



being generally much larger than and often almost or fully twice as 

 large as, those situated in the subdermal space. Terminals 2-8, usually 

 4-6, nearly straight, forming a slightly diverging tuft. Discs minute 

 and pin-head like or with toothed margin. 



Oxyhexasters vary in radius from 88/u to 80/i according to indivi- 

 duals. When changed into hexactiu-shape, the radius may measure as 

 much as 110/;. Principals exceedingly short or obsolete. Terminals 

 2-3, more usually 2, and often only one to a principal, hexactin-shaped 

 oxyhexasters being of common or even abundant occurrence. Surface 

 of terminals either smooth or rough, in which latter case the roughness 

 may develop into small basal barbs. In some specimens only rough 

 hexasters are found ; in others both rough and smooth ones occur, and 

 then the latter are generally situated in deeper parts than the former. 



Microdiscohexasters present in sparing numbers near the dermal or 

 gastral surface. 



Autodermalia consist almost exclusively of rough pentactins with 

 rays 165/* long and 8/i broad in average. 



Hypodermal pentactins comparatively small, usually not exceeding 

 4 mm. in length of paratangential rays (sometimes larger). The latter 

 are either regularly cruciate or paratropal, according to their occurrence 

 in isolated position or in groups. Their surface is smooth, but when 

 fully developed, may become uniformly and thickly beset all over with 

 exceedingly minute protuberances, exactly as I have observed in 

 Staurocalyptus pleorh aphides, Ij. or in Rossella longispina, Ij. Judged 

 from the series of specimens in my hand, it seems not improbable that 

 the power of giving the above mentioned roughness to the heads of 

 hypodermal pentactins is possessed by the present species only in young 

 state, losing that power after a certain stage of growth. So that the 

 oldest hypodermally situated pentactins as also all the prostal pentactins 

 may be rough-headed in small, but smooth-headed in large, individuals, 

 since in the latter all the rough-headed pentactins would have been shed 

 off during growth. 



In forming the hypodermal strands, the paratangential rays of the 



