432 
A. E. Yerrill — North American Cephalopoda. 
follicular glands; liver small, far forward; ink-sac small. Pen slen- 
der anteriorly, as long as the mantle. Hectocotylized arm not 
observed. All the arms bear suckers. 
Family DESMOTEUTHIDJE Terrill. (See p. 300). 
Body much elongated, mantle united to the neck by three mus- 
cular commissures. Siphon without a true valve, but with three 
peculiar, special thickenings, or raised processes* in its basal portion. 
Eyes prominent. Intestine very long ; ink-sac small. 
DesmoteuthiS Terrill. (See p. 300). 
12. Desmoteuthis hyperboreus (Steenst.) Terrill, (p. 302). 
13. Desmoteuthis tenera Terrill, (p. 412). 
Taouius Steenstrup, restricted. (See p. 306). 
14. Taonius pavo (Les.) Steenstrup. (See p. 306). 
MYOPSID^F D’Orbigny. 
Eyes usually without regular lids; the integument of the head 
sometimes becomes transparent and extends continuously over the 
eve; in some genera ( Rossia , etc.) there is a fold of skin below the 
eye, constituting a free lower eyelid, while the upper lid is adherent 
to the eye-ball ; but in Stolotenthis the lids are entirely free. The 
pupil is usually crescent-shaped, or indented on the upper side, but 
is round in Stolotenthis. Sometimes a small pore in front of the 
anterior edge of the eye connects with the orbital cavity. Siphon 
usually with a valve. 
This artificial division includes two very diverse groups, which not 
only differ widely in the condition of the eyes, but also in the nature 
of the hectocotylizatiou of the arms, and in anatomical characters. 
To one of these groups, containing the family Sepiolidce, I propose 
to apply the name Sepiolidea. 
The other division, Sepidea, includes the families, Sep idee, Loli- 
ginidee , Idiosepidoe , and perhaps Spirulidce; but the latter might, 
perhaps, be best placed with fossil forms in a division of which it is 
the sole surviving genus. 
* Of these organs the median dorsal one is larger and more complicated than the 
others (see PI. LT, fig. 2 d. m ; and fig. 4a). It seems to me probable that this organ 
is a true homologue of the foot of gastropods. 
