CEPHALOPODA OF THE HAWAIIAN ISLANDS. 



337 



Fins fairly large, a little over one-fourth as long as the mantle; each one taken singly, a little longer 

 than broad; barely separated in the medio-dorsal line by the narrow membrane covering the slender 

 gladius, which extends past them as an acute point. 



Head small, flattened, elongate, distinctly wider than the stalklike neck. Eyes large, little pro- 

 jecting; their apertures ample, with a slight obtuse anterior sinus. Funnel large, thin-walled, only 

 its tip protruding beyond the mantle margin; valve minute. Funicular locking cartilages simple, 

 with nearly straight grooves. 



Arms conspicuously unequal, their order of length 2, 3,4, 1; the lateral arms not only immensely 

 longer than those of the dorsal and ventral pairs, but also more robust in every way; dorsal arms exceed- 

 ingly short and weak, slightly recurved; the length of the second arms is about 5 to 6 times that of the 

 dorsals, the third arms about 4X times, and the ventrals 2% to 3^ times; lateral arms usually a little 

 more than half as long as the body, exceedingly slender and graceful, with a delicate narrow membrane 

 or keel along their outward aspect. Suckers small, not crowded; pedicels conical; horny rings toothed. 



Tentacles more robust, thicker, and much longer than any of the arms, attaining approximately 

 twice the length of the second pair. Club little expanded; distal portion tapering and with a con- 

 spicuous dorsal keel; at this region the inner face of the club bears four rows of minute suckers (horny 

 rings toothed), which increase regularly in size from the dorsal to the ventral row, the latter suckers 

 long pediceled and with a diameter about three times that of the dorsal ones; distally all the acetabula 

 regularly diminish in proportion, but proximally to this region those of the dorsal row about maintain 

 their size, the remaining rows diminishing in size but greatly increasing in number so that we hence- 

 forth find at least eight closely crowded series of minute subequal suckers extending for perhaps a third 

 the length of the tentacle, after which they again thin out; two of the rows continue down the stalk 

 in distantly placed alternating series for another third of its length. 



Gladius long, slender, consisting chiefly of the rhachis, and terminating in a delicate hollow cone; 

 midrib visible through the dorsal integument as a narrow horn -colored line. 



Color in alcohol everywhere a very pale brownish buff, the head and eyes darker; head brown, 

 eyes with a slaty tone. Chromatophores sparse, pale, indistinct; a longitudinally-arranged series 

 extends along the dorsal aspect of the mantle on either side of the gladius. 



Measurements of Tracheloteuthis riisei. 



Number in author's register 



Total length 



Length, excluding tentacles 



Tip of body to base of dorsal arms 



Length of mantle, dorsal 



Extreme length of fins 



Width across fins 



Width of mantle 



Width of head 



Length of — ■ 



Head 



Dorsal arm 



Second arm 



Third arm 



Ventral arm 



Tentacle 



mm. 



45 



33 



26 



17 



3 



7 



6 



Type. — In the Copenhagen Museum. 



Type locality.— Latitude 34° 40' S., longitude 7° W. (fide Hoyle). 



Distribution. — North Atlantic (Lonnberg); off coast of Ireland (Hoyle, Massy); Faeroe Channel 

 (Fowler); Messina, Sicily (Weiss, Hoyle); Gulf of Naples (Jatta); coast of Morocco (Joubin); St. Paul 

 Island (de Rochebrune); Zanzibar (Pfeffer); Indian Ocean (Hoyle); west coast of New Guinea (Hoyle); 

 Solomon Islands (Pfeffer) ; Hawaiian Islands (.4 Ibalross) ; between Honolulu and San Francisco, California 

 (Albatross); Chile (Pfeffer). 



