Dixon — On Sagartia venusta and Sagartia nivea. 127 



placing 8. aurora along with 8. venusta must be considered in- 

 sufficient. Pennington (British Zoophytes, 1880, p. 151) blindly 

 follows Dr. Andres ; but as he adduces no fresh grounds for the 

 classification which he adopts, his arrangement calls for no further 

 remarks. Professor Haddon, to whom I am indebted for many 

 valuable hints in this Paper, has authorized me to say that not- 

 withstanding what he has previously written (Proc. Roy. Irish 

 Acad., ser. 2, vol. iv. (Science), p. 527 ; Zoologist, ser. 3, vol. 

 x., p. 6), he believes it may be better, for the present, to retain 

 S. venusta and 8. nivea as separate species, and inclines to think 

 that the genus Heliactis cannot stand. 



SCIEN. TROC. R.D.S. — VOL. VI., PT. III. 



