Dibkanohi ATA. MOLLUSC A.. Ootopoda. 
cclxy 
ensued, as it requires to breathe under llie water, 
like Fishes, by ineiiiis of gills. One of the arms was 
stated to measure thirty-live feet and the body 
twenty feet, and is the largest recorded at the date 
of its capture. 
Architexithis megaptera, Verrill. — 'I’his is much 
smaller than any previously-known species, the length 
of body and head being only nineteen inches, and 
the total length forty-three inches. 'I’he color is 
reddish-brown, speckled with darker brown, much as 
in the common small Squids. 'Phis unique specimen 
was cast ashore near Cape Saple, N. B. 
Rossia Jiyatti, Verrill, is pinkish in color, thickly 
spotted with purplish-brown above, paler and more 
sparsely spotted beneath and on outside of the long 
arms; inner side of arms and front edge of mantle, 
pale. Rossia sublasvis is larger and relatively stouter 
than the preceding. Both species were taken in 
Massachusetts Bay, and are new to science. 
Order— DIBR AN CHI A'l' A. 
'I’he animal in this division is naked, and is formed 
to swim. 'I’he head is distinct; the eyes are sessile 
and prominent ; some have eight and some have ten 
arms. 'I’he body is usually provided with fins; an 
ink gland is always present. Its habit is nocturnal 
or crepuscular. 
OC'I’OPODA. 
'I’he name of this group is derived from its arms 
being eight in number. 'I’he males of the Octopods 
are comparatively scarce ; and in many si)ecies, only 
the females are known. A singular and recently- 
discovered fact is that the real males of the Argo- 
naut and several other allied forms are single arms of 
the Octopod, called liectoeotyle, which were previ- 
ously mistaken for parasitic worms. 'I'hese arms 
are found to be charged with spermatozoa. Cuvier 
describes the hectocotyle of Octopus granulatus as 
‘‘ five inches in length, and resembles a detached arm 
of the Octopus, its under surface being bordered with 
forty or fifty pairs of alternate suckers.” Dr. Kolli- 
ker, of Messina, describes another, the hectocotyle of 
'I’remoctopus, which was “adhering to the interior 
of the gill-chamber and funnel of the Boulpe. 'I’he 
body is worm-like, with two rows of suckers on the 
ventral surface, and an oval appendage on the poste- 
rior end. 'I’he anterior part of the back is fringed 
with a double series of branchial filaments (two hun- 
dred and fifty on each side). 'I’he suckeis, forty on 
each side, closely resemble those of the 'I’remoctopus, 
in miniature. Between the suckers are four or five 
series of pores, the openings of minute canals, pass- 
ing into the abdominal cavity. 'I’he mouth is at the 
anterior extremity, and is minute and simple. 'I’he 
alimentary canal runs straight through the body, 
nearly filling it. 'I’he heart is in the middle of the 
back, between the branchis. It consists of an auri- 
cle and a ventricle, and gives origin to two large ves- 
sels. 'J’here is also an artery and vein on each side, 
giving branches to the branchial filaments. Nerves 
extend along the intestine, with one ganglion. 'I’he 
VoL. I.— r 
oval sac, alluded to above, inclo.ses a small, but very 
long convoluted tube, ending in a muscuhir •!)«« de 
fesens, containing innumerable spermatozoa.” 'I’he 
hectocotyle of the Argonaut was considered a para- 
sitic worm, described under the name Tricoceplialus. 
It is similar to the others. Though the little Spirula 
is the only species found on our coast that has a shell 
resembling those larger Cephalopods, yet it will prove 
interestiiig, no doubt, to the reader to know that 
through the observations of Madame Power, who 
made extensive studies of this class, the anatomy 
and the functions of the various organs are pretty 
well understood. Fanciful notions have long been 
entertained concerning the Nautilus and Argonaut. 
Aristotle described the latter as a little ship floating 
on the surface of the sea, and, in fine weather, hold- 
ing up its sail-shaped arms to the breeze — a pretty 
fable enough, but untrue. The “ sail-like ” arms are 
used to closely envelop the delicate paper-like shell 
as a protection, and the shell is secreted from the 
edges of these “ dorsal ai'ins,” as they are called. 'I’he 
animal is not connected with the. shell by muscles, 
but holds upon it by clasping as above described. 
'V\\Q Argonautidce are regarded as ranking first. 'I’he 
next in order is 
Famii.y 00'I’0P0D1D/E. — In this group the 
arms are similar, and united at the base by a web. 
The shell is represented by two short styles, en- 
veloped within the substance of the mantle. Several 
genera are recognized. Octopus, from Octo, eight, 
indicating the number of feet or tentacular arms, as 
they are called. 'I’he body in this genus is generally 
warty or cirrhose. There are no fins. The arms 
are long and unequal ; the suckers in two rows. 'I’lie 
Octopods are the Polypi of Homer and Aristotle, 
and in later times were called Poulpe. 'I’hey are 
solitary in habit, frequenting rocky shores, but are 
very active and voracious. In this country they 
are little known, though quite large species are 
found in the waters around Florida, and in the Gulf 
of Mexico. In Naples and other Mediterranean ports 
they are exposed for sale as food. Prof. Forbes ob- 
serves that the Octopus, when at rest, coils its dorsal 
arms over its back. 'I’his would seem to indicate a 
foreshadowing of the development of the shell in 
higher species, as the Argonaut, which in the latter 
is secreted from the dorsal arm. Woodward recoi'ds 
forty-six species, and it is probable that more have 
been discovered since. 
BAIRD’S OCTOPUS {Octopus hairdi, Verrill).— 'VW\s 
is the first Cephalopod of this order that has been 
recognized as inhabiting the waters on our coast. 
During the operations of the U. S. Fishery Oom- 
mission in the Bay of Fundy, in the summer of 1872, 
several specimens of an Octopus were dredged, which 
proved to be new to science. Professor Verrill de- 
scribed the species in the American Naturalist, vol. 
vii, 1873, from which we extract the followiiig : 
“ It seems to be not uncommon below seventy-five 
fathoms, judging from the fact that we met with it 
in five different localities. All the specimens ob- 
tained were males, and it is probable that the females 
are much lai-ger than the males, as in other species 
