318 
BUIylvETiN OF THE BUREAU OF FISHERIES. 
significance, if any, is possessed by it. The ventral surface is further ornamented by a dark bluish- 
gray band bordering the heart-shaped shield. 
The following note appears on the reverse of the original station label in the handwriting of Dr, 
W. K. Fisher and affords important information regarding the appearance of this species in life (colors 
according to Ridgway’s “ Nomenclatme of GDlor”): “Tentacles, chromatophores burnt sienna, yellow 
ocher, and light red. Eye: pupil transparent, iridescent purple, blue, and emerald green; iris reddish 
burnt sienna. Body (except wings and outer test) iridescent orange, yellow, solferino, green, crimson, 
purple. Chromatophores of outer test burnt sienna and sepia.” 
Measurements or Stoloteuthis (Iridoteuthis) iris. 
mm. 
Total length exclusive of tentacles i6 
Medio-dorsal length of mantle 7 
Medio-ventral length of mantle 1 1 
Width of body 7 
Width across fins i8 
Extreme length of fin . 9 
Length of same fin at base of attachment 4 
Median length of ventral shield 7 
Dorsal-ventral diameter of body 10 
mm. 
Length of head 4 
Width of head 8 
Length of — 
Dorsal arm 4 
Second arm 5 
Third arm 6 
Ventral arm 5 
Right tentacle (left tentacle missing) 21 
Type. — Catalogue No. 214312, United States National Museum [S. S. B. 31]. 
Type locality. — The type and only specimen of the species known was taken in 153 to 142 fathoms. 
Albatross station 3832, off tlie island of Molokai, bottom of brown mud and sand. 
Remarks. — The sex of the single specimen is unknown, as owing to the brittle texture of its tissues 
it was deemed inadvisable to attempt to pry the arms far enough apart to ascertain any further details 
of structure or possible evidences of hectocotylization. It is very possible that the specimen is not 
quite adult, but its characteristic features have nevertheless attained a high development. 
Perhaps the most distinctive features are the extreme development of the dorsal commissure unit- 
ing the mantle to the head, and the immense ventral lobe. The former feature is carried to a much 
further extreme in this species than in either N. leucoptera or in 5 . nipponensis, which are the only 
other described species of the genus, while in the latter respect the only near approach is the Nectoteuthis 
pourtelesii of Verrill. According to information furnished me by Dr. Ad. Naef, 5 . nipponensis differs 
from the other species mentioned in important anatomical characters, as well as in its size and general 
aspect, and must henceforth be known as Sepiolina Naef. Its exact systematic position still seems a 
matter of more or less uncertainty, although Naef refers it to the Sepiolince. All three of the remain- 
ing species, 5 . leucoptera, S. iris, and N . pourtelesii, are characterized by the possession of a conspicuous 
pigmented shield on the ventral surface similar to that above described, have large fins, and are delicate 
gaily colored creatures of doubtless similar habits. N. pourtelesii, however, stands quite alone in hav- 
ing the dorsal border of the mantle entirely free, and S. iris likewise is in many ways very different 
from its congener. Because of this fact it also has recently been made by Naef the type of a separate 
genus, Iridoteuthis, but because its most important characters (nuchal commissure, ventral shield, 
webbed arms, etc.) are shared equally with Stoloteuthis s. s., I believe their probable relationships 
are for the present expressed better by grouping them together. The distinctive features adduced by 
Naef are the integumentary fold in the nuchal region, the large head, protruding eyes, immense fins, 
ventral protraction of the mantle, and unequal arms, but none of these features seem sufficient of 
themselves to be regarded as of more than subgeneric value. A more complete knowledge of either 
S. iris or S. leucoptera than we at present possess might, however, indicate differently. 
