ON SOME OIGOPSID CUTTLE FISHES. 
83 
Histioteuthis Ruppelli (Verany). PI. X, figs. 8 — 12. 
The specimen examined by me was purchased at Nice in 
1886, by Professor Laukester, for the museum of University 
College. 
The general external features are noted by Verany. The 
suckers of the short arms are pedunculate, globular, and show 
four large teeth on the upper margin of the chitinous ring. 
The suckers of the tentacular clubs are sessile, and have teeth 
all round the chitinous ring. 
The tentacular club is badly represented by Verany, and re- 
sembles more that figured for Calliteuthis by Hoyle (3). 
Its extremity is drawn out into a narrow strip with suckers 
in two or three rows. As the club expands we get four 
rows, two of which have much larger suckers than the other 
two. The club has a median dorsal fin, extending along 
the distal half, and an external lateral fin along the proximal 
half of the club. On the internal margin of the club are some 
small suckers and cushions or pads, alternating, and forming 
the fixing apparatus of the tentacles. These suckers and pads, 
thirteen to fourteen in number, extend, with gradually en- 
larging intervals, about halfway along the arm (PI. X, fig. 12). 
The eyes are large, but show no lacrymal sinus. Between 
the eye and funnel, and situated ventro-laterally, are two 
lappets supported by a strong nerve, lappets which are homo- 
logous with the spoon-shaped organs of Chiroteuthis, and the 
similar projections in Doratopsis (PI. X, fig. 5). 
The neck shows slight transverse and short longitudinal 
ridges, corresponding in position, but very slightly in develop- 
ment, to those of Thysauoteuthis (tc. and Ic. figs. 5 and 7, PI. X). 
The small longitudinal ridges have been called olfactory 
crests by Verrill (6) in Ommastrephes, where they are pro- 
minent, and divide the neck region into separate areas or 
facets; but only in the most ventral of these, i.e. the one 
nearest the siphon, is found, in Thysauoteuthis, a small sepa- 
rate crest, which is the homologue of the olfactory lappets of 
