86 IOWA STUDIES IN NATURAL HISTORY 
a support and cling there most tenaciously. A certain flabellate 
red and white gorgonian was very common in the dredging and 
almost always a species of simple-armed basket-fish was coiled 
closely around the branches, which it matched so perfectly in 
color that it was very apt to be overlooked. The protective col- 
oration is so commonly found in serpent stars living as sym- 
bionts on aleyonarians that many writers have noticed it. 
Alexander Agassiz says in his ‘‘Three Cruises of the Blake,’’ 
volume I, p. 310: 
‘‘Among the abyssal invertebrates living in commensalism, 
the adaptation to surroundings is fully as marked as in shallow 
water. J may mention especially the many species of ophiur- 
ians, attached to variously colored gorgonians, branching corals 
and stems of Pentacrinus, scarcely to be distinguished from the 
part to which they cling, so completely has their pattern of 
coloration become identified with it.’’ 
The subject of the coloration. of deepsea animals has long had 
a deep fascination for the writer, who has used the facts as 
going to prove, not the recent migration of these forms from 
shallow water, as believed by Agassiz; but the presence of an 
abyssal ight which would render these colors effective; and the 
light he believes to be the well-known phosphorescence so 
abundantly demonstrated in deep water. Animals lving in 
absolute darkness are invariably colorless, as in the ease of blind 
fishes, salamanders, ete. of the underground waters in. caves. 
A small ophiurid with very long arms and minute disk bear- 
ing conspicuous radial shields, had three series of club-shaped 
arm-spines, a very conspicuous madreporic body, tooth papille, 
and a curious flap-like plate overlying the basal upper arm- 
plates. Several simple-armed basket-fish allied to Ophiocreas 
were taken; and, intergrading between the ordinary serpent- 
stars and this, is an Ophiomyxa from shallow water. 
A species with branched arms, new to me, was from Station 
36, southwest of Carlisle Bay. The radial shields are very large 
and tumid, crossed by conspicuous rounded corrugations which 
are wavy in places. There are no spines nor evident granula- 
tions on the disk, and the specimen is smaller than the other 
branched forms secured. Several specimens of Astrophyton 
