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IX. Descriptions of some New and Rare Cephalopoda.
By Ricuarp Owen, Esq., F.R.S., &c., Hunterian Professor of Anatomy at the Royal
College of Surgeons in London.

Communicated February 23rd, 1836.

AMONGST other contributions to natural history which have resulted from the la-
bours of our zealous Corresponding Member Mr. George Bennett, during his late voyage
to Australia, are several new or little known marine invertebrate animals, most of which
were taken by means of the towing-net in the open sea, or among the gulf-weed. The
value of these specimens, in a scientific point of view, is much increased, by the care with
which the circumstances attending the capture of each are registered ; and I now com-
mence the fulfilment of a promise to my friend, by bringing a portion of these speci-
mens before the notice of the Members of the Society, with such observations as seem
to be worthy their attention.

The subjects at present under consideration belong to the class Cephalopoda : they are,

Ist. A specimen of the Cranchia scabra, Leach.

2nd. Four specimens of a very small nondescript species of Loligo.

3rd. The head and principal viscera of a Decapodous Dibranchiate Cephalopod,
from Port Jackson.

4th. Three specimens of a small nondescript species of Octopus.

5th. A very small specimen of the shell of Argonauta hans, Solander, with its
inhabitant (Ocythoé Cranchii, Leach) and a large cluster of ova.

With respect to the first of these specimens, Mr. Bennett, in his Journal, remarks,
“On the Ist of March, fine weather, with light and moderate trade breezes from the
south-east, thermometer Fahr. 77° to 80°, latitude 12° 15’ S., longitude 10° 15’ W.., at
8 p.m., captured, with the towing-net, several fine specimens of Hyalea dentata, and
two species of the Medusa genus ; the latter are preserved in spirits (bottle No. 4, D.).
One was very prettily marked with dark red spots.” The specimen thus distinguished
is the Cranchia scabra, now on the table’; and from the uncommon form which this very
remarkable Cephalopod presents, one cannot feel surprised that it should have been re-
ferred by its captor to a Radiate family, with which the Cephalopods bear, in more
than one respect, an analogical relation.

The Cranchia scabra is the species on which the genus dedicated to the enterprising
naturalist by whom it was first taken, was founded: it belongs to that tribe of Dibran-

1 Pl, XXI. figg. 1—5.
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104 MR. OWEN’S DESCRIPTIONS OF

chiate Cephalopods which have a pair of long peduncles superadded to the ordinary
eight arms, and to that family of Decapoda in which the rudimental shell is degraded
to the condition of a single horny style, lodged in the substance of the mantle in the
middle of its dorsal aspect.

The principal external character which entitles Cranchia to rank as a genus distinct
from Loligo and Onychoteuthis, is the continuation of the mantle with the dorsal parietes
of the head, and a consequent interruption of its free anterior margin at that part : from
Sepioteuthis, Sepiola and Rossia, it differs generically (according to the circumstances
which modern zoologists have agreed to regard as of generic importance,) not only in
the proportions and position of the pallial fins, but in the structure and connexions of
the funnel ; and in some points of its anatomy, as will be afterwards described. With
respect to the first-named character I would however observe, that species in which the
pallial fins are short and terminal in position, and which present the same condition of
the internal rudimental shell, the same connections of the mantle, and armature of the
suckers, should not be broken up into genera in consequence of differences in the form
only of the fins, especially when unsupported by corresponding internal differences of
structure; for when we compare together the different species of the uncinated Ca-
lamaries, which form the well-marked genus Onychoteuthis of Lichtenstein, we find that
scarcely two species agree in the precise contour of the fins ; and if we examine, with the
same view, the numerous members of the group Loligo, as it is now restricted, we shall
find several, as the Lol. piscatorum, Lapilaye ; Lol. Duvaucellu, D’Orbigny ; Lol. brevi-
pinna, Lesueur ; and especially the Lol. brevis of De Blainville, which closely approximate
the Cranchia scabra in the rounded contour and dorsal position of the terminal fins ; so
that were it not for the difference in the connections of the anterior margin of the man-
tle, the latter Cephalopod, notwithstanding its singular form, could not be separated
generically from the Loligines on external characters alone.

This condition of the mantle, however, has scarcely been sufliciently attended to in
the subsequent location of species in the genus Cranchia. In M. Férussac’s description of
one of the most remarkable of these recent additions, e. g. the Cranchia Bonelliana’, it is
to be regretted that no mention is made of the adhesion or otherwise of the mantle to the
posterior part of the head. The same doubts apply to the claims of the Cranchia car-
dioptera of Péron, and the Cranchia minima of Férussac, to rank in the genus in which
they have been placed: in the figures given of them by Férussac, the anterior margin
of the mantle appears to be free on the dorsal aspect, as in Loligo. In justice, however,
to the lamented zoologist who first described the Cranchia Bonelliana, and to whom the
scientific world is indebted for a most splendid monograph on Cephalopoda, now in pro-
gress of publication, it must be observed, that the limited nature of the observations
on the characters of Cranchia, and the imperfection of the specimen upon which Dr. Leach

1 Annales des Sciences Naturelles, tom. iii. (1835) p. 339.

SOME NEW AND RARE CEPHALOPODA. 105

founded the genus, render it a matter of difficulty and doubt to refer subsequently dis-
covered species satisfactorily to it. The desire expressed by M. de Férussac, that addi-
tional observations should be made on the typical species, I shall therefore endeavour
to fulfil to the best of my ability, from the specimen which Mr. Bennett has transmitted
to me’.

This specimen is smaller than the one described by Dr. Leach, but presents the same
enlarged, expanded, flaccid bag-like form of the mantle, terminated at one extremity by
a disproportionately minute pair of fins, and at the other by a head and arms of almost
equally diminutive size; so that when the tentacles are retracted, as was the case in
Mr. Bennett’s specimen, very little of the ordinary facies of a Cephalopod is presented
to the observer.

The dimensions of this specimen are as follows:

Inches. Lines.
From the posterior end of the body to the end of the tentacle out-

stretched . EYP aa Crete are fee Orel es 1 8

root of the tentacle . Ol

Length of the longest arm . 0 3
shortest ditto 0 J+

———_————_ fms... . 0 2

Breadth of the two united fins Se ha 0 3

Circumference of the thickest part of the body . anny Wie 0
iBreadthyoisthes heads i75i lrcphgactohes: Udi Mcuphced go budaice ewe emi 0 34

The body or mantle is wrinkled and flaccid, in consequence of the very small space
occupied by the viscera ; and these are situated at its anterior part, and not at the bottom
of the sac, as in Loligopsis. It is probable that at the reproductive season the enlarged
ovarium may fill more or less of the pallial cavity ; but in the ordinary state of Cranchia
scabra the disproportion of the mantle to the contained parts is very remarkable, and
unique in the class Cephalopoda ; but a similar disproportion between the viscera and pal-
lum is found in some of the Pteropoda.

The surface of the mantle in Cranchia scabra is uniformly beset with small round spots,

' The following are the observations which M. Férussac makes on the distinguishing characters of the genus
Cranchia :—* Pour fixer toutes les incertitudes a l’égard du genre Cranchie, et pour lui rapporter sans hésitation
lespéce que nous faisons connaitre, il faudrait que celles qui ont été décrites par le Dr. Leach fussent retrouvées
et mieux connues. Le caractére principal qui leur a été assigné consiste dans la forme et position terminales
des nageoires. Sous ce rapport, ce genre se confond presque avec les Calmarets, mais ceux-ci en sont bien
distingués par la forme de leurs bras tentaculaires. 1 n’est séparé des Calmars que par la forme de ces mémes
nageoires, qui sont réunies 4 leur extremité et semblent dépasser celle du sac. Dans les especes que nous y
rapportons et que nous avons pu observer, le port et l'ensemble des formes les distinguent bien plus encore des
Calmars ; mais nous ne pouvons faire la méme observation au sujet des espéces signalées par le Docteur Leach,
parcequ’il a négligé de nous donner une déscription complete et détaillée, reproche qu’on peut faire quelquefois
a cet habile observateur sans porter atteinte & sa réputation bien acquise.”—Jbid., p. 346.

p 2

106 MR. OWEN’S DESCRIPTIONS OF

the dark red colour of which had changed in the spirit to a dingy brown; these spots
occur also, but of more minute size, on the fins, and on the exterior of the arms and
tentacles. A narrow line extends down the middle of the back of the mantle, through
the whole length ; this line, when viewed by transmitted light, is transparent, the pa-
rietes of the mantle being at that part extremely thin, and containing a colourless pel-
lucid style of gelatinous consistency, pointed at both extremities, but of almost uni-
form breadth through the whole length, being very slightly contracted in the middle.
The diameter of this representative of the gladius is-,th of an inch; its length is equal
to that of the mantle.

The surface of the mantle, from which the trivial name of the present species is de-
rived, next claimed attention ; on viewing this part under the microscope, it was seen to
give off innumerable small flattened processes, varying from a thirtieth to a fiftieth of
an inch in breadth, and about a fiftieth of an inch in length, and terminating in two,
three, or four sharp-pointed processes ; these give to the outline of the mantle, under the
microscope, an irregularly denticulated appearance. The surface of the skin, though ge-
nerally smooth, presents several remarkable irregularities in other species of Cephalopods;
thus it is beset with branched papille in the Sepia papillata, with more simple obtuse
eminences in Sepia mammillata, with tubercles in Sepia tuberculata, with sharp-pointed
tubercles in Octopus aculeatus, &c., to which the aculeated lamelle of our subject make
a near approach ; it is highly probable that these different cutaneous processes serve to
indicate to the Cephalopods possessing them the nature of the surfaces with which they
may come in contact, and augment their sense of touch.

The terminal fins, which appear to have been lacerated in Cranch’s specimen, were
entire in ours ; they are of a regularly rounded form, approximated on the dorsal aspect,
and united at their bases, the united part extending about a line beyond the end of the
mantle ; they are not supported by cartilages, as in Loligo, but appear to be mere redu-
plications of the integument.

The head is principally composed of the large lateral prominent eyes; the circum-
ference of the cornea is marked with a circle of closely approximated large dark spots.

The arms have the usual conical form ; the first or dorsal pair is the shortest, as in
most Decapods ; the second and fourth nearly equal, and rather longer than the first ;
the third pair is double the length of the first.

The first, second, and third pair of arms are united at their bases by an intervening
web of greater proportional extent than is usually met with in the Decapodous Cepha-
lopods, and which is entirely wanting in the Loligines. In the Cranchia Bonelliana a
similar web extends between the corresponding arms for full two thirds of their extent.
Between the third and fourth pair of arms there is no connecting web, the interspace
being occupied by the thick round stems of the elongated peduncles. All the arms are
connected together by the external membranous lip, which gives off eight pointed pro-
cesses ; but these, instead of projecting freely, as in most of the Loligines, the Sepioteu-

SOME NEW AND RARE CEPHALOPODA. 107

this, and Sepia, are tied down or inserted at the internal surface of the base of each
arm ; the intermediate portions of the lip form an internal and smaller uniting web, ot
which the portions between the third and fourth pair of arms are the widest. With
respect to the outer web, we may, I think, justly infer, that since in the Octopodous
tribe of Cephalopods it forms, in the total absence of the mantle-fins, the sole organ of
swimming, so here it is developed, though in an inferior degree, to compensate in some
measure for the feeble condition of the terminal fins ; and we may consequently conclude
that the locomotion of the Cranchie in the watery element is principally in the retro-
grade direction.

The brachial suckers are pedunculate, and arranged in a double alternate series along
the margin of each arm; the interspace is wider than usual, and from the semitrans-
parency of the part in this small Cephalopod, the gangliated nerve which supplies the
part was beautifully distinct, as seen by transmitted light under the lens, running along
the centre of this part. The tentacles are relatively thicker than in any other Decapo-
dous Cephalopod, forming a remarkable contrast to the extremely slender and elongated
ones in the genus Loligopsis. The suckers, which are irregularly clustered at the slightly
expanded extremities, are much smaller than those of the arms, but are also peduncu-
lated ; the extremities of the tentacles are fringed on both sides with a thin entire narrow
membrane : the nerve which runs along the middle of these parts is a simple opake chord
where it is lodged in the stem, but becomes enlarged and knotty at the acetabuliferous
extremity.

The mandibles were protruded in our specimen to an extent which seemed to have
been produced by accidental compression. They were composed of a thin horny sub-
stance, of a brown colour, at the sharp-pointed extremities, and along the smooth tren-
chant margins, but elsewhere colourless. The jaws were surrounded bya thick, plicated,
but not papillose, internal lip, and by the outer thin membranous fold above mentioned.
The infundibulum was of small size, and projected in the usual situation from the man-
tle ; it differed from the same part in the genus Loligo, in being obliquely truncate at the
extremity, in such a direction that the dorsal parietes were folded down at this part,
and overlapped the ventral, as shown in the magnified figure. On laying open the ventral
parietes of the mantle, we found that the base of the funnel was not articulated by
lateral moveable ball and socket joints to the internal surface of the ventro-lateral parts
of the mantle, but that its ventral parietes became expanded, thin, and transparent, and
were inserted into, and became continuous with, the corresponding parts of the mantle.
According to Rathké, the funnel is attached in a similar manner by the adhesion of the
ventro-lateral parts of its bases to the corresponding parts of the mantle in the genus
Loligopsis. In all the other genera of Decapodous Cephalopods the funnel is articulated
to the mantle at the exterior part of its base by two enarthrodial joints, the projection
being on the mantle, and the socket on the funnel; both parts of the joint are com-
posed of cartilage, covered by a fine smooth synovial membrane ; but here we have a

108 MR. OWEN’S DESCRIPTIONS OF

singular exception to all other enarthrodial joints, for the synovial membrane does not
form a shut sac, but is continuous with the mucous membrane lining the interior of the
mantle. The convex cartilage is of an oval form in the Cuttle-fish ; in the Calamaries
(Loligo) it forms an elongated ridge; in the genus Onychoteuthis the articular ridges
commence at the anterior margin of the mantle, and extend one third of the way down
the sac, being formed by two thin lateral cartilaginous lamine, placed rather towards the
ventral aspect of the mantle ; an elevated groove in the corresponding side of the funnel
plays upon each of these ridges ; but in the genus Loligopsis the sides of the funnel adhere
to the corresponding cartilaginous lamine ; these which have been supposed to be ano-
malous and peculiar to that genus differ from the lateral cartilages of other Decapodous
Cephalopods only in their greater length and tuberculated form. In the Cranchia these
cartilages are entirely wanting, as in the Octopodous Dibranchiata. °

With respect to the anatomy of the Cranchia, I can only state that it possesses two
gills, which are provided with branchial ventricles, but that these are without fleshy
appendages ; and that it has two large inferior salivary glands. The decomposed state
of the digestive and generative viscera in the present specimen prevented any satisfac-
tory observations being made upon them,

From the preceding description it will be evident that the genus Cranchia differs from
Loligo in particulars of sufficient importance to justify a generic separation, and that in
the attachment of the funnel to the mantle, and in the absence of appendages to the
branchial ventricles, it is allied to the genus Loligopsis, which it also resembles in the
rounded form and terminal position of the fins. From this genus, however, it is distin-
guished by the adhesion of the mantle to the head, by the presence of the infundibular
valve, by the comparative strength and shortness of the tentacles, and by the webs
extended between the first, second, and third arms.

The four specimens of the small species of Loligo, which is the second on the list of
Mr. Bennett’s Cephalopods, belong to a species hitherto undescribed, and which, from
the peculiar breadth of the head, I propose to call laticeps'. The diminutive size of these
specimens, the largest of which measures only 1+ inch from the extremity of the mantle
to the end of the outstretched tentacle, suggested at first a denomination indicative of
that particular ; but when we reflect that in other genera, as Octopus, there have been
found species of still smaller dimensions than the one now described, it may ultimately
be discovered, even if adult, to be not the smallest of its genus. Mr. Bennett gives the
following note relative to the capture of these small Calamaries :—‘‘ April 5th, fine
weather ; wind east by north ; light and moderate breezes ; thermometer 68° to 72°., lat.
29° 17' north ; longitude 46° 57' west : at noon, among a mass of ‘ Sargasso weed,’ took,
in my towing net, small Sepie of a fine purple colour with dark red spots.”

' Pl. XXI. figg. 6—11.

SOME: NEW AND RARE CEPHALOPODA. 109

The specimens now present numerous spots of a deep purplish brown colour ; according
to the number and aggregation of which, the skin is darker or lighter. ‘They occur in
greatest number on the back part of the head and trunk ; are wanting on the fins, and
on the under surface of the third and fourth pair of arms; and are very sparingly dis-
tributed on the under part of the head and mantle, which are consequently of a light
colour: the most remarkable disposition of the dark pigment is that which the inner
surface of the Ist, 2nd, and 3rd pair of arms presents in the interspace of the suckers,
where it is disposed in broad, irregularly shaped, transverse stripes, corresponding to
each pair of suckers.

As the dimensions of the arms, tentacles, head, body and fins, are accurately repre-
sented in the figures (Pl. XXI. figg. 6 & 7.) subjoined, which is taken from the largest
of the four specimens, they need not here be detailed.

The head is slightly compressed, but broad ; supporting anteriorly, arms which are
relatively longer than in the Calamaries generally, the second and third pair being
nearly equal to the trunk in length. Laterally the head supports a pair of large and
well-developed eyes. ‘The orifice in the integument leading to the capsule of the eye is
spherical, proportionally large, as in Loligo vulgaris, and in the axis of vision: the
sclerotica is perforated by a smaller aperture immediately behind the preceding, so that
the capsule of the lens is immediately exposed to the external surrounding medium ; the
lens is proportionally small, but attached to the ciliary body as in the Sepia: the pig-
mentum appeared to be disposed in thick detached portions ; it was lined anteriorly by
an opake white substance, which I conceive to be the true retina, although the prin-
cipal expansion of the optic filaments is posterior to the pigment. The hyaloid mem-
brane was, as usual in this class, a strong and very distinct transparent coat.

The body of the Lol. laticeps is subcylindrical and conical, gradually diminishing in
circumference till it terminates in a point at the posterior margin of the fins, which do
not extend conjoined together beyond this part, as in the Cranchia. The anterior margin
of the mantle is free in the whole of its circumference, as in the rest of the genus Loligo.
The muscles which connect the head to it posteriorly have their origins extended along a
pair of approximate cartilaginous styles placed at the back of the neck: the anterior
part of the mantle is secured by the two strong pillars of the funnel.

On the inner surface of the mantle at its ventro-lateral aspects, are situated the two
elongated cartilaginous ridges, which are articulated, as in other Loligines, to cavities
of a corresponding form at the sides of the base of the funnel. The interior of the funnel
is provided with the usual valve, attached at the dorsal aspect of the canal. Two thin
membranes extend from the head to the back part of the funnel. The terminal orifice
of the funnel is oblique, but not to the same extent as in Cranchia scabra: in all the spe-
cimens I found four large spots of pigment arranged transversely below this orifice.
The fins are terminal and dorsal ; a space of about + a line intervenes between their ori-
gin anteriorly, whence their bases converge and are united at the apex of the trunk ;

110 MR. OWEN’S DESCRIPTIONS OF

their breadth and length are the same ; their superior contour is an obtuse angle. Their
inferior margin is rounded in the Cranchia cardioptera of Péron, to which the species
under consideration has a superficial resemblance ; the terminal fins have a semicircular
contour, and their origins are widely separated anteriorly ; they also extend beyond the
termination of the trunk: the trunk is broader in proportion to the head, and does not
diminish gradually to a point, but is rounded off at the posterior extremity. The Cran-
chia minima of Férussac may be at once distinguished from Loligo laticeps by the ex-
tension of the trunk beyond the small rounded fins, which gives a trilobate contour to
the termination of the body.

The gladius is proportionally as well developed in this small species as in the larger
Calamaries: it commences by a firm blunt anterior extremity, about one third from
which the sides begin to dilate until within the same distance from the posterior end,
towards which they converge to a point: the expanded part of the gladius is very con-
cave towards the viscera.

The mandibles have the usual form, the lower one overlapping the upper ; the dark-
coloured exposed part is of greater extent than in the Cranchia. They are surrounded
by a tumid inner circular lip, minutely plicated transversely ; the external membranous
lip presents a free and slightly indented internal margin ; its external margin is produced
into eight pointed processes, which, as in Loligo todarus and Lol. Piscatorum, are tied
down to the inner surface of the arms, and are without rudimental suckers.

Of the arms, the 3rd pair are the longest ; the 2nd, 4th, and Ist pair successively di-
minish in length, but in a very slight degree. The suckers are arranged at the margins
of the inner surface in a double alternate series, attached by moderately long and slender
peduncles, having a lateral insertion ; the diameter of the suckers is half that of the part
of the arm which supports them. In the tentacles the suckers are confined to the dilated
extremities, as in Loligo vulgaris : they are here arranged in three or four irregular series,
and present the following peculiarity :—the peduncles, which are at first filiform, dilate
at their commencement, before they are attached to the sucker, like the calyx of a
flower ; and the cavity of the sucker is continued in this dilated part (Pl. XXI. figg. 8, 10.)

With respect to the anatomy of this minute species, we cannot be surprised that it is
in every respect as complex as that of the largest of the genus of which it presents all
the external character: just as in the highest class of animals, the harvest-mouse exem-
plifies as perfectly the mammiferous type of organization as the elephant. The gills in
Loligo laticeps are attached through their entire length by a membrane to the sides of
the mantle ; the branchial hearts, to which the above connecting membranes have a re-
lation of coexistence, are provided with small fleshy appendages, as in other Calamaries,
and indeed as in all the Dibranchiata which have the funnel articulated with the
mantle.

The divisions of the vena cava, and the extremities of the visceral veins, have thick-
ened spongy coats, with a tolerably smooth and equal external surface: the systemic

SOME NEW AND RARE CEPHALOPODA. 111

ventricle is lozenge-shaped, and elongated in the direction of the axis of the body, but
the two lateral angles which receive the branchial veins are not on the same plane, the
right being most anterior. The digestive organs presented no deviation worthy of
notice ; the anus was provided with the two small aliform valves or appendages.

The small species of Octopus’ which next comes under consideration, is, like the
small Loligo above described, an inhabitant of the Sargasso or Gulf-weed. Two spe-
cimens of this Cephalopod were taken on the 5th of April, and the third on the following
day, in latitude 30° 31' north, longitude 44° 7' west. Mr. Bennett mentions them as
‘small Sepie” of a purplish colour. i

The Cephalopods of the genus Octopus are generally found near the coast, where they
seek their prey among the rocks, creeping on their eight legs with the body carried
above or behind the head ; they are less calculated for living in the open sea than the De-
capods, which are provided with an additional pair of fins. That singular oceanic phe-
nomenon, the Sargasso or Gulf-weed, serves however, in place of a shore, as a resting-
place to the small species now under consideration, and affords food and shelter to in-
numerable other curious Invertebrata: indeed an accurate fauna of this floating mass of
marine vegetables would be a most interesting addition to Zoology.

The largest of the three specimens of Octopus collected by Mr. Bennett measured
from the extremity of the sac to the end of the longest arm exactly an inch and a half,
the length of the sac or body being barely half an inch. The first peculiarity which may
be noticed is in the position and attachment of the eyes, which, instead of being con-
tained in a capsule as in the common Poulp, project uncovered from the sides of the
head in the form of large dark-coloured spherical bodies: in this structure we are re-
minded of the Nautilus, in which the organs of vision not only project from the sides of
the head, but are supported on peduncles: the prominence of the eye-balls in the
Argonauta, and still more in the Octopus hyalinus, is an approximation to the struc-
ture just described in the present species. Those alone, who have witnessed the per-
severing activity, power, and velocity of motion exercised by the Octopus when en-
gaged in its destructive practices amongst a shoal of fishes, and who have seen it with
its beak buried deep in the flesh of a victim held fast in the irresistible embrace of its
numerous arms, in an instant simultaneously dissolve the attachment of its thousand
suckers, and, disengaging itself from its prey, dart like an arrow from the net that has
been cautiously moved towards it for its capture, can form an adequate idea of the
acuteness of visual perception and powers of action with which this singular and un-
shapely Cephalopod is endowed.

In the present species the form of the body is ventricose, but slightly tapering to its ex-
tremity ; the mantle is connected by a broad continuation of the integument to the back

1 Pl, XXI. figg. 12, 13.
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112 MR. OWEN’S DESCRIPTIONS OF

of the head; the greatest breadth of the body is 4 lines ; the breadth of the head, in-
cluding the eyes, is half an inch. Of the eight arms which radiate from the anterior
part of the head, the first or dorsal pair is the longest, as is the case in many species
of Octopus ; the second pair is nearly the same length as the first ; the third pair, which
is commonly the longest in the Decapods, is here scarcely half the length of the first ;
the fourth pair is nearly two thirds the length of the first.

The musculo-membranous web which is usually extended between the bases of all
the arms in the Octopi, is in this species developed to the ordinary extent between the
four dorsal arms only: the webs between the second and third, and the third and fourth
arms are very short ; that between the fourth pair is wanting. From this peculiarity I
propose to name the species Octopus semipalmatus. The suckers are sessile, and are
arranged in a double close-set alternate series on the margins of the internal surface of
the arms, with a broader interspace than is usually observed (figg. 12, 13. Pl. XXI.)

The eyes are of proportionally large size, and present a dark colour, in consequence
of the pigment shining through the sclerotic coat. The sclerotic is perforated by a cir-
cular aperture in the usual situation ; and as the dermal cornea, which covers the ante-
rior part of the sclerotica in the common Poulp, is absent in this species, the capsule of
the crystalline lens is exposed, as in the Nautilus, to the sea-water. The funnel has the
usual exterior form: it is without a valve; but at the sides of its base there is a struc-
ture approaching to the articulation by which it is united to the mantle in the Decapo-
dous tribe of Cephalopods. Immediately above the insertion of each lateral pillar there
is a small transverse crescentic ridge which rests upon a similar ridge projecting from
the side of the mantle (see a, 0, fig. 13. Pl. XXI.) ; neither of these prominences however
is supported by cartilage, as in the Decapoda. In the Octopus catenulatus there is a
similar structure, but the projection on the mantle is shorter and more prominent ; in
the Argonauta the articulation of the sides of the funnel is still more complete, and is
constant in all the known species of that genus’.

With respect to the anatomy of this small Cephalopod it may be observed, that in
the presence of a crop, in the lateral insertion of the gullet into that receptacle, in the
muscular stomach, the spiral laminated bag, and the folded intestine, it accords with
the generic type of structure presented in the common Poulp (Octopus vulgaris, Cuv.).
The ink-bag is similarly buried 1n the anterior part of an undivided large liver : the biliary
ducts are without glandular appendages : the follicles appended to the branchial divisions
of the vena cava, are elongated, and hang from the exterior of the vessels ; the branchial
hearts are without fleshy appendages; the branchie are connected by membranous
bands to the sides of the mantle ; the branchial amine present a zig-zag folding, as in

' The preceding examples of the infundibular jomts in the genus Océopus diminish the value of that cha-
racter as distinguishing Ocythoé from Octopus. See Dr. Leach’s account of Ocythoé Cranchii,—Phil.
Trans. 1817, p. 295.

SOME NEW AND RARE CEPHALOPODA. 113

the Argonaut ; there are fifteen pairs in each gill. The peritoneum, or external mem-
brane of the viscera, was remarkably mottled with large purple-red spots: I have ob-
served the same disposition of a brown pigment on the peritoneum in the Argonaute’.

The pigment which gave the purplish tint to the skin when the animal was alive,
appeared to have been driven from the surface; for on removing the cuticle, which was
remarkably thick and elastic in this small Cephalopod, only some small brown spots
were perceptible in the vesicular rete mucosum : these were aggregated chiefly on the
dorsal aspect of the body and head.

As the generative organs were scarcely developed in either of the specimens, it is
probable that they may not have arrived at maturity, and the species consequently may
be assumed to attain a greater size than that of the largest individual in the collection,
which measures only 1+ inch from the bottom of the sac to the extremity of the longest
arm. The prominence of the eyes, the structure of the funnel, the proportions of the
arms, and the partial development of the interbrachial web, will however afford the
means of distinguishing this species when it is again met with.

The very interesting specimen cf the Paper Nautilus, or Argonaut, which forms part
of Mr. Bennett’s collection of Cephalopoda, is thus noted in his journal :—

““March 7th. Fine weather ; light and moderate south-east trade breezes; therm.
from 81 to 84; lat. 4° 43’ south, long. 17° 37' west. I did not capture a single spe-
cimen with the net during the day; but at 8 p. m. I procured some small specimens of
Ezxocetus, and also an excellent specimen of an Argonauta: on placing it in sea-water it
expanded its tentacula, but did not attach itself to the glass, or move about. Early on
the following morning I found the animal dead in the glass of sea-water in which I had
placed it on the previous night, and on moving the shell to take it out, the soft parts fell
out. After the animal was out of the shell, a cluster of ova was seen attached to the in-
voluted part of the shell ; somewhat resembling, but in the recent state more beautifully
shown than in, the engraving of apparently a similar specimen in the Appendix to
‘Tuckey’s Narrative of the Congo Expedition.’ On placing the shell in spirits, the
cluster of ova floated out like a diminutive plant of a pure white colour, presenting a very
elegant appearance. After being preserved a day in spirits, much of this beautiful ap-
pearance was lost. The body of the animal was of a dark reddish colour, which colour
was also given to the upper part of the shell, either naturally or imparted to it by the
animal; the remainder of the animal was of a dirty white with minute purplish dots ;
and the arms were also speckled underneath of a similar colour : the suckers were white.
These cephalopodous animals are not (and I consider correctly) regarded as the true
inhabitants of the shell, but merely parasitical inhabitants ; and the animal not having

* A development of pigment on the serous membrane of the abdomen is observable in many fishes, and in
some reptiles, as Anguis fragilis, Ophisarus ventralis, and some species of Lacerta, Cuy., and in Agama atra,
where the peritoneal pigment is almost black.

a2

114 MR. OWEN’S DESCRIPTIONS OF

the power of either producing or reproducing the shell, must be sufficient to decide that
the one usually found in it, is not the original inhabitant of the shell.”

With respect to the remark with which my friend concludes his observations on the
present specimens, I need scarcely observe that there is no doubt that the determination
of the power possessed by the Ocythoé of reproducing, or otherwise, the Argonaut shell,
would be an experimentum crucis, and settle the long-agitated question. I do not find,
however, among the notes left by Mr. Bennett in my charge, any other observations re-
specting the Argonaut than those above transcribed ; and the experiments hitherto re-
corded touching the reproduction of the shell by the Cephalopod inhabiting it, have been
deemed by the experimenters as proving that the shell is the veritable production of the
Cephalopod.

The shell of the specimen under consideration belongs to the species Argonauta hians
of Solander, and the animal is the Ocythoé Cranchu of Dr. Leach, so called on the sup-
position of its being a parasitic inhabitant. It is worthy of remark, that in the present,
as in every other instance of which I have cognizance, where the Argonauta hiuns has
been taken with its inhabitant, the latter has invariably presented characters as speci-
fically distinct from those of the Cephalopods inhabiting the Argonauta Argo and Argo-
nauta tuberculata as are those of the latter from each other : and the same circumstance
holds good with respect to a nondescript species of Argonaut’, taken by Capt. P. P. King
in the South Pacific ocean ; in which both the shell and its inhabitant differ specifically
from the three recent species hitherto described. I am aware that it has been urged by
the advocates of the parasitic nature of the Ocythoé, that the Argonaut shells taken
possession of by different species of Ocythoé in different parts of the ocean would be most
likely to be also of distinct species : but the constancy of the correspondence between the
Cephalopod and the shell, both as to specific peculiarities and size, affords strong pre-
sumptive evidence of their relation to each other being something more than mere acci-
dental adaptation®.

' This species I have called, from the colour of the animal and its shell, Argonauta rufa.

2 Since the preceding observations were written, the following facts have been added to the natural history
of the Argonaut. M. D’Orbigny states that he has observed specimens of the Ocythoé in Argonaut shells, of
which the margin of the aperture was entire, and in a membranous or soft state; whence he concludes that the
shell had recently received an addition at that part, and that this addition was due to the Cephalopod inhabiting
it. It is difficult to assent to the explanation of this fact offered by M. De Blainville*, viz. that the true con-
structor had been very recently expelled by the Ocythoé, for in that case the very delicate margins of the shell
would surely have been injured by the Cephalopod whilst violently expelling the rightful owner, and usurping
possession of the fragile shell.

Two experimenters (Madame Power and M. Rang), at different periods, and in different places, have broken
and remoyed portions of the Argonaut shell while inhabited by the living Cephalopod, and have observed that
the latter repaired the breaches by a secreted substance, not indeed similar to the originally formed shell, but
which one of the experimenters, M. Rang, compares in this respect with the shelly matter secreted by the

* Annales d' Anatomie et de Physiologie, Mai, 1837.

SOME NEW AND RARE CEPHALOPODA. 115

The most interesting circumstance to be noted in Mr. Bennett’s Argonaut, is its di-
minutive size, in connection with the large mass of ova which it has formed, excluded

Limaces to repair accidental breaches in their shell, and which also differs from the originally formed shell.
‘When, however, fractures occur near the margin of the shell, they are repaired by a substance identical with the
rest of the shell, as has been shown by Mr. Charlesworth *; but whether these reparations are due to the Ce-
phalopod, or to some yet unknown Mollusk, can of course only be determined when the question is decided
respecting the real constructor of the Argonaut.

The true use and disposition of the palmated arms of the Ocytho? have been determined and described by
M. Sander Rang. The base of each of these arms passes out of the shell at the angle between the summit and
auricular process of the free margin, and the membrane expands upon the outside of the shell, and meets its
fellow at the flattened keel. These expansions are transparent in the living Argonaut, and are compared by
M. Rang to the thin lobes of the mantle which the living Cowry spreads over its shell. Thus, when the Argo-
naut creeps at the bottom of the sea, it carries the shell above it, supporting it by means of the palmated arms,
and moves along, its head being downwards, by means of the other three pairs of arms. M. Rang, who has
long devoted himself to the study of Malacologic, and who is allowed by M. De Blainville to be ‘ parfaitement
au courant de l'état de la question,’ derives from the preceding observations a conviction that the Ocythoé is the
true constructor of the Argonaut. M. De Blainville, however, sees in the palmated arms only the analogous
organs of the claspers at the extremity of the tail of the parasitic Paguri.

I have frequently, however, seen Paguri, and especially young ones, in shells very disproportionate to their
own size; but I have never observed an analogous disproportion between the Argonaut shell and its occupant.
In a series of six small Argonauts, Cephalopods aud shells, captured at the same time in the South Pacific
Ocean, all individuals of the same species (Arg. rufa, O.), but all differing by slight gradations in size, and of
which five are young, and without ova, and totally fill the shell, there is an exact accordance between the size
of the shell and the size of the inhabitant; a corresponding gradation of size is maintained in both. In a series
of several small and very young specimens of the Argonauta Argo, which I examined whilst they were tempo-
rarily deposited by Madame Power in the hands of Mr. Charlesworth, and which, from the shght difference
of size, must have exhibited stages of growth differing at most by a few days only, there was the same exact cor-
respondency between the size of the Cephalopod and that of its shell. Now to explain this accordance between
the Cephalopod and shell on the parasitic theory, we must have recourse to the supposition that the Argonauts
change their shell at very brief intervals : indeed the chief business of their lives would be in that case to hunt
out, seize, and dispossess the (assumed, but yet unseen) true constructor of the shell, in order to present so con-
stant a harmony in the relative proportion of the Cephalopod and shell which my observations on two series of
two different species of Argonaut have shown to exist.

On the same occasion that I compared together the interesting series of the young specimens of Argonauta
Argo, 1 examined the small vermicular bodies supposed by Madame Power to be the newly-excluded young of
the A. Argo; these were, however, young specimens of the parasite of the Argonaut described by Cuvier under
the name of Hectocotylus, which in the disposition of its numerous suckers, offers a remarkable resemblance to
the arm of an acetabuliferous Cephalopod.

I cannot help further observing that the apparent strength of the main argument for the parasitic nature of
the Ocythoé, is its real weakness, since it arises from a view of analogy contracted within the artificial limits of
the systematist. The argument runs thus: Because the Ocythoé has no muscular attachment to its shell, and
because it is said to leave it and return to it at will, and to have no fixed relative position (?) to the shell, and
because there is no other festaceous Mollusk in the same predicament, therefore the occupant of the Argonaut
shell is a parasite. But surely we are justified in extending our views of analogy in such a question beyond the
lmits of an artificial group, and we have not to look very far into the animal series before we find, in the Ser-

* Magazine of Natural History (New Series), 1837, p. 526.

116 MR. OWEN’S DESCRIPTIONS OF

from its oviducts, and attached to the shell. When first captured, the ova were pressed
down into the back part of the shell; but upon the removal! of the superincumbent
weight of the animal, it would appear that their own elasticity, combined perhaps with
the absorption of fluid, and the coagulation of the albumen by the alcohol, had tended
to occasion their protrusion forwards.

The longest diameter of the shell is nine lines ; the transverse diameter six lines : the
length of the animal, from the fundus of the sac to the end of the longest arm (the se-
cond), one inch four lines ; the length of the sac, from its fundus to the free margin at the
base of the funnel, five lines. The funnel extends beyond the base or uniting membrane
of the ventral pair of arms; it is, as in the other genera of Octocera, unprovided with
an internal valve; but is articulated at its base by two lateral joints to the mantle.
The account of this structure in the Philosophical Transactions does not convey an
adequate or correct idea of what the present specimen of Ocythoé Cranchii presents ;
there appears indeed to be a typographical error in Dr. Leach’s description. I find on
each side of the base of the funnel, immediately above the insertion of the lateral mus-
cular pillars, a small firm fleshy tubercle, above which there is a small depression ; on the
inside of the mantle immediately opposite, there is a corresponding tubercle and cavity,
but their positions are reversed, the tubercle being above the cavity; thus the promi-
nences in the funnel and mantle are reciprocally received into the opposite depres-
sions, and the funnel and mantle are locked together by a double ball and socket joint,
in the degree of apposition necessary for the complete fulfilment of the vigorous alter-
nating muscular actions on which the respiratory function depends (a, ), fig. 14. Pl. XXI.)

The arms in Mr. Bennett’s Argonauta hians were not rigidly contracted, as happens
generally with those specimens which are immersed alive in spirits ; but were flaccid and
flexible, and well adapted for determining their exact proportions and form. The length
of the first pair was nine lines ; the number of suckers on each of these was thirty-six ;
they extend, as in Argonauta Argo, along the circumference of the terminal membrane,
but not to the same distance. I could not trace them with the microscope further than
about one third of the way down from the anterior margin of the membrane ; while in
Arg. tuberculata they may be traced along more than half the circumference of the velum ;

pule, e. g., instances of soft-bodied invertebrates secreting as true a shell as the calcareous Argonaut, yet having
as little of a muscular attachment or uniform position to the shell, and as much freedom of quitting their shell
and returning to it, as the Argonaut.

With respect to another argument*, in favour of the parasitism of the Cephalopod of the Argonaut, which,
from an imperfect knowledge of the circumstances attending the development of the ova of the Mollusca, was
supposed to be afforded by a difference in the size of the ova of the Ocythoé, and of that which Mr. Gray regards
as the nucleus of the Argonaut shell; I refer to it only because it has been adopted by M. De Blainville in
his résumé of the Argonaut question as valid in favour of the parasitism of the Ocythoé: it has, however, since
been abandoned by its promulgator, being founded on erroneous premises. (See the Magazine of Natural
History, 1837, New Series, p. 247.)

* See Proceedings of the Zoological Society for September, 1834.

SOME NEW AND RARE CEPHALOPODA. MES

and in Arg. Argo they are visible to the naked eye, and extend round the whole of the
circumference of the same part. From this disposition of the suckers it would appear as
if the characteristic structure of the first pair of arms arose from their extremities being
bent back upon themselves and united to the stem by means of a thin membrane. These
membranes are most developed in the Mediterranean species, the Argonauta Argo, and
have been described by naturalists and poets from Aristotle and Callimachus down to
Cuvier and Byron, as serving the office of sails ; the animal being supposed to have the
power of rigidly extending the soft fleshy arms which support the membranes, and of
maintaining the latter tensely outstretched to meet the breeze. It is scarcely necessary
to observe, that the structure of the parts in question is incompatible with this hypo-
thesis of the use of the vela in navigating the frail boat of the Argonaut’.

In the present species the terminal membranes of the first pair of arms are relatively
smaller than in Arg. Argo or in Arg. tuberculata: in the latter they are broader than
they are long : in the Argonauta hians they present contrary proportions. In the present
specimen in which the vela are beautifully entire, they measure from the commencement
of the reflected portion of the arm, (or what would be considered as the end of the arm)
to the lower margin of the web, four lines, their breadth is three lines. The length of
the second pair of arms is ten lines, the number of suckers, fifty-six ; the length of the
third pair eight lines, number of suckers fifty-two ; the length of the fourth pair seven
lines, the number of suckers twenty-eight.

Dr. Leach observes, in his description of Ocythoé Cranchii, that ‘‘ all the internal or-
gans are essentially the same as in the Polypus.” (Octopus of Cuvier, loc. cit., p. 294.)
We found, however, that the Argonauta hians, like the Argonauta Argo, receded trom
the naked Octopods, Octopus and Kledone, and approached the Decapods in the struc-
ture of the branchial hearts, which are provided with a fleshy appendage ; and in the
form of the appendages to the vena cava which are shorter and thicker ; and in the re-
lative position of the lozenge-shaped ink-bag, which is not buried in the substance of
the liver, but lies in its anterior concavity. The inferior salivary glands are also rela-
tively smaller.

The following differences, as compared with the Octopus, occur in other internal or-
gans which adhere to the type of structure which characterizes the Octopodous tribe of
Dibranchiata. The crop increases in width as it approaches the stomach. The lami-
nated pancreatic bag is of a triangular form, and not spirally disposed ; the two simple
biliary ducts enter at its apex. The two oviducts are devoid of the circular laminated
glands which surround them about the middle of their course in the Octopus ; they are
also disposed in four or five convolutions as they pass behind the roots of the branche,
and they terminate at a greater relative distance from the base of the funnel.

1 Since the above was written, it has been ascertained by direct observation, that these vela, or rather vela-
menta, have not only a relation of coexistence, but one of direct physiological import, to the development of the
shell in the Argonauts, serving as the organs both of secreting and of retaining this part. See the observations
of M. Rang, Comptes Rendus del’ Acad. des Sciences, Avril 24, 1837.

118 MR. OWEN’S DESCRIPTIONS OF

The affinity of the Argonauta to the Decapodous Cephalopods is further indicated by
the inferior development of the mediastinal septum which divides longitudinally the
branchial chamber. This septum in Eledone is complete and muscular throughout, ex-
cepting a very small proportion of its inferior part. In the Octopus, in which this
septum is well described and figured by Cuvier, as the ‘‘ bride antéricure qui lie la bourse
a la masse viscerale',” a greater proportion of the lower part is membranous than in
Eledone. In the Argonauta the muscular part of the septum is reduced to two narrow
and delicate strips, which arise from the posterior part of the cranial cartilage, descend
obliquely forwards, intercept the termination of the rectum and ink-passage, to which
they serve as a sphincter, and then expand in the vertical direction, to be inserted along
the middle line of the internal surface of the anterior part of the mantle: a membrane
is continued from their upper part to within a short distance of the margin of the mantle ;
and another from their lower part extends downwards, and terminates opposite the base
of the gills ; the branchial chambers intercommunicate both above and below this sep-
tum. In Sepiola the muscles corresponding to the bride antérieure of the Octopus are
developed in the same degree as in the Argonauta ; but the membranous part of the
septum above them is wanting, while that which is continued from their inferior mar-
gins is more complete. In the Calamaries both these muscles and the septum of the
branchial chamber are wanting.

With respect to the nervous system of the Argonauta, I find in a large specimen of
the Argo, that the brain, when viewed from the superior or dorsal aspect, presents, as in
Octopus, an anterior, white, flattened, tranversely oblong band, and a posterior raised
convex semilunar mass, which terminates by a semicircular border posteriorly, the ex-
tremities of which are directly continued, to form or join the posterior nervous collar
of the wsophagus. The great lateral nerves of the mantle come off from the posterior
subcesophageal mass, precisely as in Octopus ; and instead of extending down in a pa-
rallel direction as low as the roots of the gills, as represented in the splendid figure by
Delle Chiaie ', they diverge, penetrate the short muscles, analogous to the brides laté-
rales in the Poulp, and terminate in the stellated ganglions opposite the upper extre-
mities of the gills, and immediately below the base of the funnel : by some unaccountable
error, these nerves, in Delle Chiaie’s figure, which some of our compilers have copied,
are made to come off from the optic ganglions. The lateral muscles above mentioned
are the analogues of the great shell-muscles of the Nautilus Pompilius ; they are more
strongly developed in Loligo and Sepia than in Octopus, but have the same origin in
each, the same attachment to the capsule containing the rudimental shell, and are al-
ways perforated by the great lateral nerves of the mantle: they are perforated by the
corresponding divided and ungangliated nerves in the Nautilus, in which these mus-
cles acquire the maaimum of development. In the Argonauta, which has no muscular
attachment to its shell, and has no internal testaceous rudiment, the corresponding

‘ Poli, Testacea Utriusque Sicilie, vol, iii. pars 1™, posthuma, 1826.

SOME NEW AND RARE CEPHALOPODA. Lee)

muscles have the smallest development, and the mantle-nerves which perforate them
are, prior to the formation of the ganglion, relatively the shortest that are met with in
the Dibranchiate order.

I carefully examined the ova of Mr. Bennett’s small specimen, but obtained no re-
sults bearing upon the interesting question before alluded to, the development of the
embryo not having proceeded to the degree necessary for the appearance of the shell,
supposing it to be formed in ovo. The observations recorded in the ‘ Philosophical
Transactions,’ by Mr. Bauer (1817), and in the ‘ Zoological Journal,’ by Mr. Broderip,
(vol. iv. p. 57.) are, for the same reason, inconclusive as to this point.

The ova of the Argonauta hians were nearly of the same size as those of the Arg.
Argo at a similar stage of development, viz.
but they are of a more regular oval form, not tapering to the end opposite the attach-
ment of the peduncle. Examined with transmitted light, they are composed of an ex-

th inch in length, and -,th in diameter ;

terior, smooth, colourless, transparent, tough, elastic, cortical tunic; next of a more
delicate membrane (the chorion), containing a straw-coloured transparent albuminous
fluid : in this fluid there was an irregular mass of semi-opake granules, in which was im-
bedded an opake dark vitelline body, surrounded by a membrane and pellucid fluid.
The form and proportion of the opake vitelline body and its transparent investing mem-
brane varied in size and shape in different ova: I have carefully figured one of the most
remarkable in this respect (fig. 15), in which for a moment I entertained the exhilarating
idea, that the nucleus of the real shell was contained within it: on tearing open the ex-
ternal tunic, however, the contained substance turned out to be nothing more than the
yolk, separated by an intervening stratum of clear fluid from the transparent membrana
vitelli, and the whole substance of the opake mass separated into the flakes, granules,
and globules of oil, of which the vitellus is usually composed : there was not a trace of
any consistent parts of an embryo, nor the slightest particle of calcareous matter.

The mutilated Decapodous Cephalopod, obtained at Port Jackson, New South Wales,
and transmitted to me by Mr. Bennett, consisted only of the head and principal viscera,
and was consequently too imperfect to allow of its being satisfactorily determined, even
as to its genus. But as the suckers were arranged in a double alternate row on each of
the short arms, it was evidently not a Sepia of Cuvier, while the denticulated margins
of the horny rims of the suckers show that it may have belonged either to the genus
Sepioteuthis, Fér., or Loligo, Cuv. As in some species, both of Sepioteuthis and Loligo,
the outer lip gave off eight short processes, on the inner surface of which, near their ex-
tremity, were three or four small suckers, attached by peduncles, and having precisely
the same structure as those of the eight large exterior arms. In this repetition of the
ordinary series of cephalic prehensile processes, we may perceive an evident analogy to
the internal series of processes (labial tentacles) which exist in the Nautilus. In some
species of Calamary, indeed, as in the Loligo Pealii, Le Sueur, the acetabuliferous labial

VOL. I1.—PART II. R

120 MR. OWEN’S DESCRIPTIONS OF

processes are more developed than in the present specimen from Port Jackson. In Lo-
ligo corollifera, Tiles, these labial processes have been compared by Bojanus to the in-
ternal shorter series of tubercles of a Medusa. But this structure illustrates only in a
very remote degree the relation of analogy subsisting between the Cephalopods and
Radiaries.

The structure of the tongue, pharynz, and glandular appendages, presented nothing
remarkable. The wsophagus was slender, and continued of uniform breadth, as in the
Decapods generally, to the stomach, which presented the usual gizzard-like structure.
In the Octopods, as in the Nautilus, the esophagus dilates into a crop’.

The rectum in this Cephalopod was furnished with two lateral processes (fig. 16.
pl. XXI.), of a flattened triangular form, and evidently adapted to constitute a valvular
apparatus for the protection of the anal aperture. They are attached at opposite sides
of this transversely extended orifice by their acute angles, from which a ridge is ex-
tended to the middle of the opposite base, so that when the valves are folded down upon
the vent (as in the figure above the number of reference,) the ridges fit into the aperture,
and accurately close it. In the Cuttlefish (Sepia officinalis, Linn.) the corresponding
processes are of a rhomboidal form, with a thicker ridge on the side next the anal aper-
ture, which they are thus adapted to defend against any foreign substances which may
obtain entry into the pallial cavity. In Onychoteuthis and in Loligopsis the anal append-
ages are long and slender: in the latter genus Rathké* compares them to antenne ; and
since in these Cephalopods they cannot act the part of mechanical guards, it may be in-
ferred that they perform the function of instruments of sensation, and convey the sti-
mulus to contract, to the muscular sphincter which closes the outlet of the alimentary
canal. It is interesting to notice the relation of coexistence which these appendages
bear to the lateral fins; for they are only present in those Cephalopods which have
the power of propelling themselves forward, and in which their use is therefore obvious,
as the orifices of the branchial cavity, in which the intestine terminates, are directed
forwards. In the Octopods the anus is not provided with these appendages.

Of the remaining viscera of the Decapod in question I have only to notice the repro-
ductive organs: these were of the female sex, and exhibited the ova both in the ovary,
where they were inclosed in reticulate calyces, as in most Cephalopods, and in their
passage through the oviduct, where the ova show the true character of their external
surface, which is perfectly smooth and polished’.

1 It is evident from this difference of structure in the two groups of Dibranchiata, that Aristotle took his ex-
cellent description of the digestive organs of the Malakia either from a Sepia or Teuthis: he says, “Mera 0é 76
orépa &xovow oicopayor paxpoy Kal orevdy, éxdpevoy Cé rovTou mpddopor péyay Kal repupepy dpyOwWon.”’—Hist. de
Anim., lib. iv. ec. 19.

2 Mémoires de l Acad. Imp. de Petersburgh, tom. ii. (1833), p. 169. ‘ Ueber Perothis,’ &c.

3 [ am not aware of any modern account of the mode in which the ova of the Cephalopoda are impregnated,
taken from actual observation. Aristotle, whose History of Animals is still the richest in details of the habits

SOME NEW AND RARE CEPHALOPODA. 12]

The female organs of generation in the Cephalopodous class present five principal
modifications of structure. The ovarium is single in all, but sometimes, as in the
Cuttle-fish, it is divided by a septum.

1. In the Nautilus there is one oviduct, which traverses an elongated gland at its ex-
tremity : there is also a superadded nidamental gland, which has no connection with the
oviduct, but is attached, as in the Pectinibranchiate Gastropods, to the parietes of the
branchial chamber.

2. In Sepia, Sepiola, Rossia, Sepioteuthis, and some species of Loligo, there is also
one oviduct with a glandular termination ; but the nidamental glands are two separate
bodies, detached from the mantle, and having no communication with the oviduct.

3. In Onychoteuthis, Loligo sagittata and some other Calamaries there are two distinct
oviducts, each terminated by a glandular organ, and also two separate nidamental glands.

4. In the Octopi and Eledone there are two oviducts, each of which traverses a glan-
dular organ, situated about the middle of its course: there are no detached nidamental
glands.

5. In the Argonaut the two oviducts are convoluted, and have glandular coats
throughout their extent,but without partial enlargements: there are no separate nida-
mental glands.

and ceconomy of the Cephalopods, gives two descriptions of the act of impregnation. In the fifth book of the
Historia Animalium it is stated that the Polypus (Octopus or Poulp), the Sepia (Cuttle-fish), and the Teuthis
(Calamary), all copulate in the same manner; the male and female having their heads turned towards one an-
other, and their cephalic arms being so coadapted as to adhere by the mutual apposition of the suckers. In
this act the Poulps are described as seeking the bottom, while the Cuttles and Calamaries are said to swim
freely about in the water, the individual of one sex moving forwards, the other backwards. Aristotle also observes,
that the ova are expelled by the funnel, which the Greeks call gvon7jpa; and some, he adds, assert that the
coitus takes place through this part. From the position of the terminal orifice of the oviduct at the base of the
funnel, and the inclination of the penis towards the same part, the latter supposition derives some probability,
especially with respect to the Sepia and Sepioteuthis, in which the male organ is well developed; but in these,
as in all other Cephalopods, true intromission is physically impossible. From the dense nature of the external
covering which the ova derive in their course along the efferent passages, it is very improbable that they can be
impregnated otherwise than internally, and before the nidamental covering is laid upon the thin smooth chorion
which invests the ovwm externally, prior to its escape from the oviduct : the descriptions of Aristotle may there-
fore relate to some such imperfect connexion as takes place in the Salamanders, &c. It is worthy of remark,
indeed, that the differences in the situation in which the coitus is said to take place in Aristotle’s description
corresponds with the modifications of the locomotive powers in the three genera treated of. It is only, for ex-
ample, in the Sepia and Loligo that posterior fins exist, enabling the individuals to swim forwards. The
second account of the impregnation of the Malakian ova occurs in the 12th Chapter of the 8th Book of the
Historia Animalium, where the generation of fishes is treated of. ‘‘ When they (fishes) bring forth, the male,
following the female, sprinkles the ova with his semen. The same thing happens to the Malakia, for in the
genus Sepia, wherever the female deposits the ova the male follows and impregnates them: this possibly hap-
pens in like manner to other Malakia, but hitherto it has been observed in the Sepia alone.” The ova of the
Sepia, however, are precisely those which, of all Cephalopods, from the density and thickness of their coats, are
the least likely to receive the impregnating influence after having been excluded.

R 2

122 MR. OWEN’S DESCRIPTIONS OF

The Decapod here described presented the second type of the generative organs. The
ovarium was of an elongated form, and of great extent ; it was filled with reticulate ovi-
sacs, containing ova in all stages of development, and must have occupied nearly the
whole of the posterior half of the abdominal cavity. The single oviduct came off from
the middle of the left side of the ovary, and descended obliquely to the bottom of the
ovary, where it was dilated by a cluster of smooth and polished ova; it was then bent
suddenly upon itself, and near the anterior extremity of the ovary entered the terminal
gland, which was expanded at its commencement, and after suddenly contracting, gra-
dually tapered to its free extremity. The ova presented an oval form, and were three
lines in length. The first or membranous portion of the oviduct had thin, semitrans-
parent, and very dilatable coats. The two detached nidamental glands were of a longer
and narrower form than in the Sepie, but thicker, and of greater relative size, than in
the Loligines. They presented the usual transversely laminated structure and anterior
longitudinal fissure, in which the glutinous secretion is moulded into the thread-like form,
adapted to connect the ova together as they escape from the true oviduct, with which
these glands have often been confounded. But besides the above parts, which are evi-
dently subservient to the generative function, I found two small, round, flat, fleshy bo-
dies attached to the anterior extremity of each of the two nidamental glands. They
had no cavity, and were destitute of any duct or outlet, and had no other connection
with the nidamental glands than by the cellular tissue. Their texture was compact,
with a few minute cellular cavities about the centre: they were of an orange colour.
In the Cuttle-fish there is a corresponding body, similarly situated, but single and
trilobate, consisting of two lateral slightly compressed conical portions, united by a
middle oval lobe (see fig. 19. pl. XXI.). The dorsal surface of the lateral lobes is flat-
tened ; the opposite side excavated to receive the superincumbent extremities of the
ovarian glands: to these glands the trilobed body is attached by a tough connecting
membrane. On making a section of a lobe of the body in question (as in fig. 20.), its
texture appears to be dense, and somewhat granular, with minute cells at the centre, which
contain a caseous substance. In Sepiola the corresponding body is single, as in the
Sepia, and is similarly attached to the anterior extremities of the nidamental glands.
In the Loligines, and in the Cephalopod taken by Captain Ross on the shore of Boothia,
and which, being the type of a new genus, I have described under the name of Rossia’,
there are two fleshy bodies, as in Mr. Geo. Bennett’s Cephalopod. Each body in Rossia
(see fig. 18. hh pl.X XI.) is attached by cellular tissue to the anterior part of the corre-
sponding nidamental gland (g g), and is excavated by a deep groove, situated close to
the aperture of the gland. From this structure, and the position of the glands, we
might infer that they assisted in moulding the nidamental secretion, or in applying it to
the ova.

If we take into consideration the texture of these enigmatical and hitherto undescribed

' Zoological Appendix to Capt. Sir John Ross’s Voyage.

SOME NEW AND RARE CEPHALOPODA. 123

bodies’, their bright colours, and their relative position to the generative apparatus, we
may perceive an evident analogy between them, and the corpora succenturiata, or supra-
renal bodies of the vertebrate animals.

The preceding dissections, combined with those which I have made from time to time
on other Cephalopods, belonging to the genera Sepiola, Rossia, Loligo, Onychoteuthis,
Sepia, Octopus, Eledone, Argonauta, and Nautilus, have, in connection with physiolo-
gical views, suggested ideas of the natural affinities and formation of the different groups
of Cephalopods, which differ in some respects from those expressed in the previous clas-
sifications of these highly organized invertebrate animals; and I am induced to offer
them to the consideration of zoologists, as they appear to me to be more in accordance
with the best principles now recognised in the subdivision of other molluscous classes.

The systems of classification of the Cephalopods existing in the best works of the pre-
sent day differ from each other in some material points. In one, e. g., no characters
of ordinal importance are recognised ; but the class is immediately subdivided into se-
veral minor groups, of the value of tribes or families: in other classifications, where a
primary division of the class into two or three orders is adopted, the characters are de-
rived sometimes from modifications of the locomotive organs, but more frequently from
different conditions of the shell: and one can scarcely suppress a feeling of surprise
that the modifications of the tegumentary system, the low relations of which are so
generally recognized in the subdivision of other classes of Mollusca, should be adopted
for the classification of the Cephalopods by so many systematic writers of authority on
Malacology.

Lamarck (Philosophie Zoologique, 1809,) divides the Cephalopods into three orders ;
first, into those which have a multilocular sheil ; second, those which have a unilocular
shell ; and third, those which are without either.

Tt is obvious also that the modifications of the dermal system mainly govern the dis-
tributions of the Cephalopoda in both editions of the Regne Animal of Cuvier. In the
edition of 1817 the Naked Cephalopods or Seiches constitute the first family, to which
the Nautili, Belemnites, Hippurites, Ammonites, Camerines, and even the Argonauts, are
severally regarded as equivalent groups. In the edition of 1829 considerations of the
affinities indicated by internal organization prevail so far as to lead to the suppression
of the group of Argonauts, and its union with the Seiches. The other modifications
consist of the additions of families, including the later discovered chambered shells pre-
senting new modifications of structure, such as the Actinocamaz of Miller, and the Ca-
marines, or microscopic chambered shells.

In 1821 Mr. Gray” proposed a classification of the Cephalopeds in which a primary
division into three orders was distinctly recognised, and names applied to them indi-

' Cuvier makes no mention of them, and they appear by subsequent anatomists to have been confounded with
the nidamental glands.
* London Medical Repository, 1821.

124 MR. OWEN’S DESCRIPTIONS OF

cative of modifications of the shell, which he terms ‘ Protector’. The Seiches, or Naked
Cephalopods of Cuvier, are subdivided into two orders, of which the first, under the name
of Anosteophora, corresponds with the Poulpes of Cuvier, and with the Octopoda of Dr.
Leach’s arrangement of 1817, presently to be noticed; while the second order, Sepie-
phora, is equivalent to the Decapoda of Leach, or to the remaining Sciches of Cuvier’s
system. All the Cephalopods with chambered shells are collected together into a third
order, under the name of Nautilophora.

The reformed classification of the Cephalopoda contained in the Malacologie of M. De
Blainville (1825)’, though much more truly expressive of the natural affinities of its ob-
jects than that proposed by Mr. Gray, still reposes on the insecure basis of tegumentary
modifications. The whole of the Seiches of Cuvier are here raised to the rank of an
Order, under the name of Cryptodibranchiata ; and the author, guided by the knowledge
of their internal organization, rightly uses the characters derivable from the modifica-
tions of their internal shell, as indicative merely of the subdivisions of this order. M.
de Blainville made also ancther important step in advance, by separating the Cephalo-
pods with microscopic chambered shells, under the name of Cellulacea, from those with
siphonated shells, which he terms Polythalamacea. Subsequent researches have since
proved that the Cellulacea of M. De Blainville ought to be removed altogether from the
class Cephalopoda. The classification of the Cephalopods adopted by M. Férussac in
the great work still in progress of publication is essentially the same as regards its pri-
mary divisions as that of M. de Blainville, but the nomenclature of M. D’Orbigny is
preferred. All the Cephalopods, e.g., without chambered shells, form the first order, under
the name of Acetabuliferes ; all those having siphonated chambered shells form a second
order, termed Siphoniferes ; and the non-siphonated microscopic chambered shells consti-
tute a third order, under the name of Foraminiferes.

Now in consequence of the subordinate character on which all the preceding classifica-
tions are founded, there is a violation of natural affinities in the formation of the primary
groups. The genus Spirula, e. g., as well as the Belemnites, and other congeneric ex-
tinct Cephalopods with internal chambered shells, are united, solely on account of the
polythalamous structure of their shell, with Cephalopods of an inferior grade of organ-
ization, as the Nautilites, while they are separated from those which possess the dibran-
claate or higher type of structure,—a type of structure which the laws of coexistence all
but demonstrate to have been exemplified in the Cephalopods with internal chambered
shells, first quoted, viz. Spirula and Belemnites.

The natural affinities of the Cephalopods seem to have been still less regarded in that
distribution of the species in which the Dibranchiate Decapoda are joined with all those
Cephalopods possessing chambered shells in one primary division of the class, which
M. de Haan* terms Adherentia ; and in which the Dibranchiate Octopoda are raised to

' In 1815 this author proposed a binary division of the Cephalopods, which he preferred to term Cryptodi-
branches, into Cryptodibranches nus and Cryptodibranches testacées.—Journal de Physique, t. \xxxiii. p. 244.
2 Monographia Ammoniteorum, &c., 8vo, 1825.

SOME NEW AND RARE CEPHALOPODA. 125

the rank of an equivalent section, under the name Libera. The primary division of
Cephalopods, proposed by M. Deshayes’, into the two orders Octopodes and Decapodes, is
essentially the same as that of M. De Haan, as the latter group combines the naked
or dibranchiate species with the Nautilacea of De Blainville.

Thus it will be seen that most of the preceding schemes are based on the modifications
of the shell or its analogue, and some of them, as that proposed by M. Férussac, have
been published since the modifications of structure in those Cephalopods which inhabit an
eaternal chambered shell have been pointed out. It is this circumstance which has
chiefly induced me to state here my views of the distribution of the Cephalopods, founded
in part on the dissection of the Nautilus Pompilius, and on a comparison of its organ-
ization with that of the Cephalopods with internal shells, so far as indications of their
structure can be obtained from the hitherto imperfect descriptions of the recent Spirula,
and from the remains of the Belemnites. But before I proceed to detail these views I
shall briefly adduce the few examples of the classification of the Cephalopods, in which
an attempt is made to distribute these highly organized Mollusks into groups founded
on considerations of structure of higher importance than tegumentary or testaceous
characters.

The first classification of this nature is due, as might have been expected, to a highly
accomplished classical Naturalist, well versed in the zoological writings of Aristotle.
This Naturalist, Schneider, to whom we owe the best translation of the ‘ Historia Ani-
malium,’ is the first of the moderns who attempted to revive the philosophical views
which guided the Father of Natural History in his distribution of the Malakia or Cephalo-
pods. For this group of Cephalopods Schneider proposed the name of Octopodia, compre-
hending therein the species in which two superadded elongated slender arms are present,
but which were distinguished by Aristotle from the ordinary eight arms, under the name
of ‘ Proboscides.’ Schneider* divides the class into two groups, which are characterized
as follows :—

1. Pedes octoni breves, promuscides bine, venter pinnatus, ossiculum dorsi. Ex. Sepia,
Loligo, Teuthis, &c.

2. Pedes octoni longi basi palmati, absque promuscidibus, pinnis et osse dorsali. Ex. Po-
lypus, Moschites, Nautilus (or Argonauta) ; and indicates a third, founded on Rumphius’s
description of the Nautilus Pompilius, with the following character : Pedibus lobatis, seu
digitatis absque acetabulis.

The classification proposed by Dr. Leach’, which in one respect is inferior to Schnei-
der’s, is also essentially based on the modifications of the organs of locomotion. In this
scheme Dr. Leach leaves entirely out of consideration the chambered shells, and appa-
rently restricts the class Cephalopoda to the naked species. These he divides into two

1 Encyclopédie Méthod. 1830.

° Sammlung Vermischter Abhandlungen der Zoologie, &c., 8vo. 1784.
3 Zoological Miscellany, vol. iii. 1817.

126 MR. OWEN’S DESCRIPTIONS OF

orders, according to the number of cephalic appendages, the presence or absence of pal-
lial fins, and the connexions of the mantle to the neck.

The same principles are adopted in the present classification of the Cephalopods in our
National Museum ; a third order being added to the Octopoda and Decapoda of Leach,
corresponding with the Polythalamacea of M. De Blainville, and characterised, according
to the structure of the Nautilus Pompilius, by many short arms destitute of suckers.
Weigman, also, in his Handbuch der Zoologie, (1832,) makes each of the two divi-
sions of Leach’s Cephalopods equivalent to the Polythalamacea of De Blainville, which
he terms Nautilacea.

But the general organization of the Octopodous and Decapodous Cephalopods, and espe-
cially their respiratory and circulating systems, correspond so closely, and both at the same
time deviate so widely from the condition of the corresponding systems in the genus Nau-
tilus, that the inequality of the value of the three primary divisions of the Cephalopods
adopted in the synopsis of the British Museum must be obvious: characters, moreover,
taken from modifications of the locomotive and prehensile organs alone, or associated
with such minor particulars of organic structure as are applied by Dr. Leach in his
subdivision of the Naked Cephalopods, can only be viewed as indicative of secondary
subdivisions of the class.

A mature consideration of the relations subsisting between the modifications of the
Cephalopodic type of structure presented by the Pearly Nautilus, and the siphonated
chambered shell, has led me to perceive that the presence of a siphonated chambered shell
of itself is not a character of ordinal importance: the organic conditions which may
justly be regarded as indicating ordinal! distinctions relate rather to the amount of deve-
lopment of the chambered shell, and to its relative position, either as protecting, or
protected by, the soft parts of its fabricator. Where the chambered shell is limited to
its hydrostatical functions, and is buried, like an air-bladder, in the interior of the Ce-
phalopod, and is no longer subservient to its defence, we may infer that an ink-bag will
be superadded to compensate for the absence of a large defensive case ; and, at the same
time, that the relief from the incumbrance of a shell so developed wili be accompanied
by an increase of locomotive powers, demanding those modifications of the respiratory
and circulating functions which are undoubtedly of ordinal importance.

Now as the Nautilus Pompilius presents an inferior or subdivided type of the respi-
ratory organs, and as the function of respiration in this species has not the advantage
of those superadded hearts for accelerating the course of the venous blood through the
gills which the naked and more active Cephalopods possess, and as these most inter-
esting physiological modifications are related to the size and external position of the
shell, I feel myself justified in grouping with the family represented by this existing Si-
phoniferous species, the extinct Orthoceratites, Ammonites, and all other Siphonifera of
which the soft parts were, in like manner, contained in and protected by a chambered
shell. ‘To the group thus characterised I have applied the term Tetrabranchiata, derived

SOME NEW AND RARE CEPHALOPODA. 127

from the number of the gills in the Nautilus’. The Cephalopods with internal cham-
bered shells, heretofore classed with the Siphoniferous Cephalopods which constitute the
preceding order, I would join with all the other Naked Cephalopods, to form a second
order, under the term Dibranchiata*, having reference to the number of gills, viz. two.
This number is constant in all the ‘ Seiches’ of Cuvier, and is associated with the pre-
sence of two-branchial hearts, besides the single systemic heart, and with an ink-bag :
there can be little doubt that the same type of structure is exemplified in the Spirula,
from what has been determined respecting its external characters’.

The subdivision of the Tetrabranchiata must necessarily be determined by the modi-
fications of the shell and calcareous parts of the beak, since, excepting in one genus,
no other parts of the animals now remain for the study of the naturalist. With reference
to the higher or Dibranchiate order, as extended by the admission of the Spirule
and Belemnites, we may with propriety adopt the character afforded by the number
of cephalic arms as indicative of a primary subdivision, and include the Dibranchiates
having internal chambered shells, with the Calamaries and Cuttle-fishes in a tribe called
Decapoda, or those which have two long peduncles superadded to the eight ordinary
arms. ‘The character afforded by the internal chambered shell seems hardly of suffi-
cient value to separate the Cephalopods having that part, as a third tribe distinct from
the ordinary Decapods ; for the difference is at least as great between the minute
horny style of the Sepiola and the sepium of the Cuttle-fish, as between this latter
and the internal calcareous apparatus of the Belemnite. Moreover, Lamarck’s figure
and the descriptions of the Spzrula demonstrate so close a resemblance between its lo-
comotive organs and those of the Cuttles and Calamaries, as to afford additional rea-
sons for not placing them further apart than as families in the same tribe.

The tribe Decapopa of the Dibranchiate order of Cephalopods may be subdivided into
four families. Of these the Spirulide, represented by the Spirula australis, Lam., must
be regarded as next in the order of affinity to the Tetrabranchiate group. The Belem-

1 Memoir on the Pearly Nautilus, 1832, p. 56.

* The introduction of these new words for the primary divisions of the Cephalopods into a science already
overloaded with Greek compounds, requires perhaps some apology or explanation.

The groups which the terms Dibranchiata and Tetrabranchiata respectively indicate are not equivalent to the
orders or primary divisions in any previous classification of the Cephalopods, and I could not, therefore, have
adopted the ordinal names of my predecessors without the hazard of ambiguity or error.

The order Dibranchiata, e.g. differs from the Cryptodibranchiata of M. De Blainville, and from the Acetabu-
lifera of M. D’Orbigny, in the addition of the families Spirulide and Belemnitide; and my Tetrabranchiata dif-
fers from the Polythalamacea and the Siphonifera of the same authors, in the absence of those genera in which
the chambered and siphonated shells are internal. Under these circumstances, therefore, where a presumed
deeper insight into the organization and affinities of a class of animals leads to an actual modification of its
subdivisions, new terms for such modified groups seem preferable to the risk of confusion which would arise
from applying the same name to two different collections of objects.

% The discovery by Dr. Buckland, of the remains of the ink-bag in the extinct Belemnites, justifies the con-
clusion from the laws of coexistence, that these Cephalopods also possessed two gills and two branchial hearts.

VOL hie b AR Dy Tit. 5

128 MR. OWEN’S DESCRIPTIONS OF

nitide, including the genera Belemnites, Actinocamax, Pseudobelus, &c., offer the trans-
ition from the Spirulide to the Cephalopods in which the internal shell is still calca-
reous, but in which the traces of the camerated structure become very obscure. Such
is the condition of the shell in the Sepiade, or third family, represented by the common
Cuttle-fish (Sepia officinalis, Linn.). Besides the character derivable from the modifi-
cations of the shell, the species hitherto observed of this family present lateral fins, ex-
tending the whole length of the mantle; and the marginal horny lining of the suckers
is entire, or only minutely denticulated ; but this latter is a character rather of generic
than of family importance.

The fourth family of Decapodous Dibranchata, I propose to term Teuthide, from the
name rev0oc, applied by Aristotle to the Calamaries or typical genus of the family. The
principal character of this family reposes on the horny condition of the shell, the rudi-
ment of which exists as a single lamina, more or less developed, and encysted in the
substance of the dorsal aspect of the mantle: the form of the body in this family is
mostly elongated and cylindrical, and the pallial fins are generally broad, shorter than
the body, and terminal. The genera included in this family may be arranged in two
groups, according to the structure of the funnel. In section A, or those in which the
funnel is articulated at its base to two internal ventro-lateral cartilaginous prominences
of the mantle, may be ranked the genera Sepioteuthis, Bl. ; Loligo, Cuv. ; Onychoteuthis,
Lichtenstein ; Rossia, Owen ; Sepiola, Leach. In all these genera, moreover, the funnel
is provided with an internal valve. In section B, or those in which the funnel is ad-
herent at the ventro-lateral parts of its base to the mantle, may be ranked the genera
Cranchia, Leach, and Loligopsis, Lam. The latter genus, besides the common absence
or loss of its superadded tentacles, manifests an affinity with the Octopodous Dibran-
chiates, in the absence of the valve of the funnel; and in both genera the transition to
the same group is indicated by the absence of the fleshy appendages to the branchial
hearts.

The uninterrupted continuation of the mantle with the posterior part of the head or
neck, and the confluence of the pallial fins at their posterior extremities, which Dr. Leach
uses as family characters, are indicative of generic distinctions only: the proportional
length of the arms is even of still less importance.

The tribe Ocroropa, besides the absence of the long peduncles, is characterised by
the absence of the pallial fins, and infundibular valve. I subdivide this tribe into the
families Testacea and Nuda. Of these the first is represented by the genus Argonauta,
and its affinity to the Decapodous group is manifested by the presence of appendages to
the branchial hearts, and by the ball and socket articulations of the funnel. The first
or dorsal pair of arms support membranous expansions for secreting, repairing, and re-
taining the shell.

The naked Octopods have all or part of the arms connected at their bases by a broad
web ; the first pair being elongated, and gradually diminishing to a point. The funnel

SOME NEW AND RARE CEPHALOPODA. 129

is generally attached to the sides of the mantle ; the branchial hearts are without fleshy
appendages ; the biliary ducts without follicular appendages ; the shell is represented
by two short, brittle, horny or gelatinous styles, encysted in the dorso-lateral parts of
the mantle. This family includes the genera Octopus, Leach, and Eledona, Leach. The
following is a tabular view of my classification of the Cephalopods :—

Classis. Ordines. Tribus. Familie. Genera.
Eledona.
INH bog ab orale O
O ctopus.
( OcTopopa .... - Argonauta.
CSTACEU ae Neeine Bellerophon, Bia,
Loligopsis.
a 3
DIBRANCHIATA Costner.
Be ep anectasetit Sane Teuthide .. Sepiola.
2 Rossia.
E | b. s Onychoteuthis.
Loligo.
5 l Decapopa..... Sepioteuthis.
SI ] Sepiade...... Sepia.
fa Belemnitide.... Belemnites, &c.
a Spirulide ..... Spirula.
o) Yip ens Hie Ammonites, &c.
T i “-* *) Baculites, &c.
. TETRABRANCHIATA!. . 0.052020 eee ie eas Navciecwae!
PLA ted i anarn Orthocera, &c.
PLATE XXI.

Cranchia scabra, dorsal aspect ; natural size.

Cranchia scabra, ventral aspect ; natural size.

Cranchia scabra, head, with the mantle, a, a, laid open to show the attachment
of the funnel 6, by means of the muscular membranous processes or
‘brides’, c, c. Magnified.

4, Head and mouth of Cranchia scabra, showing the webs, a, connecting the six
dorsal arms; the outer lip, b, the inner lip, c, inclosing the gaping man-
dibles. Magnified.

5. A small portion of the skin of Cranchia scabra, showing the denticulate pro-
cesses, highly magnified.

6. Loligo laticeps, dorsal view ; natural size.

7. Loligo laticeps, ventral view ; natural size.

9. A sucker of one of the short arms, magnified.

go ie

1 The subdivision and grouping of the very numerous members of this order must repose entirely on a study
of the modifications of the shell and other enduring parts; and I have here introduced provisionally the two
principal divisions as proposed by M. D’Orbigny, merely for the purpose of citing the principal genera in ex-
emplification of the Tetrabranchiate Order.

s 2

130 MR. OWEN’S DESCRIPTIONS, ETC.

Fig. 8 & 10. A sucker of one of the peduncles, magnified.

11. Head of Loligo laticeps ; a, outer lip, b, inner lip ; magnified.

12. Octopus semipalmatus, dorsal view ; natural size.

13. Octopus semipalmatus, ventral view, with the mantle laid open, magnified ;
a, the crescentic ridge on the side of the base of the funnel, articulating
with 6, the corresponding cavity in the mantle : the other parts correspond
with those in the common Poulp (Octopus vulgaris).

14. Argonauta hians, Sol., withdrawn from the shell; (three times the natural
size of the specimen figured). The mantle is laid open to show the vertical
septum, and a and 8, the dislocated joint of the funnel of the right side.

15. An ovum of the same specimen, magnified.

16. The anal valves of a Decapodous Cephalopod (an Sepioteuthidis species 2) from
Port Jackson. The upper figure shows them closed ; the lower figure, open.
Natural size’.

17. The organ of hearing of the Cuttle-fish (Sepia officinalis): both vestibular
cavities are laid open, showing the obtuse elastic processes which are in
contact with the capsule of the otolithe or calcareous body ; the capsule is
laid open on one side. Natural size.

18. Female organs of generation of Rossia palpebrosa, Owen. Natural size.

a. Ovum in its reticulate ovisac or calyz.
Ovisac, in the act of discharging its ovum.
. Discharged ovisacs.
. Oviduct.
e. Terminal gland of the oviduct.

f.f. Ova passing through the oviduct.

g.g. Accessory ovarian or nidamental giands.

h.h. Corpora succenturiata.

19. Corpus succenturiatum of the Cutéle-fish (Sepia officinalis).
20. The same; one lobe bisected, to show its structure.

ua fo

' As this sheet was going through the press, I received from Mr. George Bennett three entire specimens of
the Cephalopod from Port Jackson, of which the viscera are described in the preceding pages, proving it to be a
species of Sepioteuthis.

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