POLYPS AND CORALS. 69 



Color, in alcohol : lo 1 wer part of column yellowish 

 brown ; upper part greenish brown ; disk and tentacles 

 dark olive-green. 



Bonin Islands. Dr. William Stimpson. 



The above description has been made from a specimen 

 well preserved in alcohol. It is doubtless somewhat con- 

 tracted, but retains nearly the normal form, and all the 

 organs are well shown. 



SUBFAMILY, DISCOSTOMIN^E. 



Discostomince Verrill, Trans. Conn. Acad., I, p. 461, 1869 (non Dis- 

 cosomfR Duch. and Mich., Supl., p. 27, 1864). 



Column apparently without verrucae or lateral open- 

 ings. Tentacles numerous, short, often verruciform or 

 with globose ends. Disk broad, with verruca, papillae, 

 or small tentacle-like organs, arising from the same radi- 

 ating chamber with the corresponding tentacle, and often 

 scarcely differing from it in form. 



This singular group is remarkable in having the tenta- 

 cles but little developed in length and often confounded 

 with verrucse or other organs which arise between the 

 mouth and tentacles, and are usually arranged in radia- 

 ting lines. These appear to agree in everything, except 

 position, with the verrucas, papillae, and similar organs 

 that arise from the sides of the radiating chambers along 

 the lateral surface of the body, below the tentacles, in 

 BunodeSi'Anthopleura, and many other genera. 



In addition to Discostoma, and the other forms here de- 

 scribed, it appears to include Ricordea Duch. and Mich., 

 which becomes compound by fissiparity ; Draytonia D. 

 and M., with colored tubercles outside the tentacles ; and, 

 probably, Corynactis Allman. Other described genera 

 may belong here, but since authors in describing these 

 animals have not stated whether the "tentacles," scat- 

 tered on the disk, arise each from a distinct chamber, 

 like true tentacles, it is impossible to determine their 

 true affinities with certainty. The genus, Aureliania 

 Gosse, may belong here, as also Capnea Forbes, but 



