A. E. Verrill—Marine Fauna of North America. 137 
Position in Wave-length 
La normal spectrum. in yoo05000"™. 
ndigo, 
Bpissigh blue, t wie aie: 
-blue, 770 4790 
Ultramarine (genuine), . 785 4735 
Ultramarine (artificial), 857 4472 
It has been shown then, 
1st. That the color of indigo is really a greenish blue when 
it is used as a pigment or in solution. 
2d. The color of the dry cake is not only very black, but 
variable according to the mode in which it is handled. 
Taking all this into consideration, it would appear desirable 
to allow the term indigo to fall into disuse, and to substitute 
for it ultramarine, the color of the artificial variety being 
intended. 
Art. XIX.—Notice of recent Additions to the Marine Fauna of 
the Eastern Coast of North America, No.8; by A. E. VERRILL. 
“ae eee to Zoology from the Museum of Yale College. 
o. XLV. 
CEPHALOPODA, 
Octopus obesus, sp. nov. 
Suckers of all the arms moderately large, nearly globular 
Am. Jour. Sc1.—Tuirp — Vou, XIX, No. 110.—Fzs., 1880. 
] 
