CEPHALOPODA. 13 
webbed; tentacles very long, not retractile; siphon short, without 
attachment to the head, or valve. Shell or gladius snaall, long, 
lance-like. 
Family ToysAnoreutHip®. Body rather long or oval; mantle 
supported by cartilaginous ridges and grooves ; arms free ; 
siphon united to the head by two bands. Gladius dart-like. 
Family OnycnoreutHip®. Body long, cylindrical; mantle 
supported by cartilaginous projections; eyes with a lachrymal 
sinus; arms or tentacles armed with hooks ; siphon with or 
without bands and valve. Gladius generally lancet-form, with 
an end-conus. 
Family OMMATOSTREPHIDH. Body long, cylindrical; arms short, 
armed with suckers only ; the short tentacular arms non- retrac- 
tile; siphon valved, united by bands to the head. Shell small, 
lancet- form, with an end-conus. 
B. Decapoda calciphora. Internal shell calcareous. 
a. Septophora. Shell blade-like. 
Family Sepp. Eyes covered by skin; littoral. Body oval, 
with long lateral fins, uniting behind ; mantle supported by carti- 
laginous | tubercles fitting into sockets on the neck and siphon ; 
arms with suckers, tentacular arms entirely retractile ; siphon 
valved. Shell (cuttle-bone, sepion or sepiostaire) broad, flat, 
thickened internally by numerous plates, terminating behind in 
a hollow, imperfectly chambered apex or mucro, without con- 
necting siphon. 
b. Phragmophora. Shell forming a series of chambers traversed 
by a stphon. 
Family BreLosepip#. (Fossilonly.) . Shell like Sepia, but the 
walls of the chambers of the mucro pierced by small holes, 
indicating the existence of a connecting siphon. Animal un- 
known. 
Family BeLemnitm®. (Fossil only.) Animal, arms with 
hooks. Shell a pen (pro-ostracum) attached to a chambered cone 
(phragmocone), the partitions of which are pierced by a sub- 
marginal, ventrally -placed siphunecle; at the hinder end the 
phragmocone is enveloped by a rostrum. 
Family Sprrunip#. Animal, body oblong, with minute ter- 
minal fins; mantle supported by a cervical and two ventral 
ridges and ‘@TOOV es; arms with six rows of minute cups; tentacu- 
lar arms elongated ; siphon valved. Shell spiral, w horls on the 
same plane, not in connection, chambered ; chambers connected 
by a ventral siphon, invested by a series of cone- shaped tubes, 
one for each chamber. The shell is placed vertically in the end 
of the body, and is held in place by side flaps of the mantle. 
The above succession of families indicates a progression from 
the so-called naked octopods (with the internal shell represented 
